Although the new generation of gene editing technology CRISPR/Cas9 has many advantages, it is often inefficient when performing mutations at a single base level. Due to the uncertainties in DNA double-strand breaks, homology directed repair (HDR) based on donor template occurs only in the actively dividing cells, however, non-homologous end joining (NHEJ) works in the whole cell cycle, therefore, it seems to be insufficient when traditional CRISPR/Cas9 performs gene editing at a single base level. The advent of the base editor (BE) has greatly relieved this dilemma. The cytosine base editor (CBE) or the adenine base editor (ABE) can both achieve C·G to T·A or A·T to G·C conversion without causing double-strand breaks, thus greatly improving the application value of single base editing. This paper focuses on the principle, development, application and existing problems of CBE, in order to provide useful reference for the application of efficient single base mutation tools in biomedical and animal husbandry production.

Wool curvature is one of the key factors affecting wool quality. The decrease of wool curvature and the change of wool strand from compactness to fluffy will lead to the decline of wool quality, which will affect the value of fur. Hair follicle is a skin accessory organ that regulates hair growth and plays an important role in the formation of curvature of hair. In recent years, some progress had been made in the study of curvature formation of hair fibers in sheep, mice and other animals, as well as in the regulation of hair follicle development. In this paper, the characteristics of wool fiber structure were introduced, and the important regulatory signaling pathways related to hair follicle development and their effects on hair curvature were elaborated. In summary, the research progress of wool curvature related genes and proteins were reviewed. The biological mechanism of wool curvature and hair follicle development were summarized in order to provide theoretical basis for the study of molecular mechanism of wool curvature and hair follicle development, and to provide some references for improving wool curvature characteristics.

The safety of egg product which causes public concern is always the hotspot of research. As the popularization of welfare poultry rearing, the chance of eggs being contaminated by microorganisms increases. In addition to strengthen feeding management, it is also important to strengthen the egg's own protective barrier to resist bacterial invasion. The cuticle, an invisible layer on the surface of eggshell, is formed in the uterus at 1.5-2.0 h before oviposition. The cuticle is a natural defense preventing microorganism penetration across the eggshell. It was reported that eggs with thicker cuticle had a lower bacteria penetration rate compared with the eggs with thin cuticle layer. The eggs' cuticle is mainly composed of glycoprotein (90%), polysaccharides (4%), lipids (3%) and inorganic phosphorus in the form of hydroxyapatite crystals (3%). The eggshell cuticle contains several antimicrobial proteins, like lysozyme C, ovotransferrin, ovocalyxin-32, which can prevent bacterial trans-shell penetration effectively. Moreover, the cuticle also has many other functions:termination of calcite crystal growth during shell formation, as a lubricant to facilitate egg rotation in the uterus, extension the eggs' storage time by regulating the exchange of water and air. In this paper, the structure, biological function, evaluation method and factors affecting the quality of cuticle are reviewed, and the existed problems are discussed.

Tuberculosis (TB) is caused by the infection of Mycobacterium tuberculosis (Mtb). It is a severe pulmonary disease and an important public health burden at present. It is estimated that about 23% of the world's population is infected with Mtb. Although many Mtb-infected people do not eventually develop active TB disease, there is still millions of people die of TB worldwide every year. Great effort has been made to reveal the pathogenic mechanism of Mtb in order to ultimately overcome TB. The inflammasomes are a group of polyprotein complexes that accumulate in the cytoplasm of infected or damaged cells. Inflammasomes can recognize pathogen-associated molecular patterns (PAMPs) or host-derived damage-associated molecular patterns (DAMPs). So, inflammasomes play important roles in the host defense against many infectious diseases. In this review, we summarized the activation mechanism of inflammasomes and the research progress on the roles of inflammasomes in the host defense against Mtb infection.

The objective of this study was to compare the differences in estimating genetic parameters using different methods, and provide a reference for breeding method development of carcass and meat quality traits in Beijing You chickens in the future. The genetic parameters for carcass and meat quality traits of Beijing You chickens were estimated using the traditional best linear unbiased prediction (BLUP) and genomic best linear unbiased prediction (GBLUP) methods. Six hundred and fifteen cooks with similar weight at 100 days of age were selected from the Beijing You chicken population with relatively complete pedigree. At 100 days of age, a total of 7 traits of these individuals were measured, including body weight (BW), eviscerating percentage (EP), breast muscle percentage (BMP), leg muscle percentage (LMP), abdominal fat percentage(AFP), tenderness (T,expressed by shear force) and intramuscular fat (IMF), and their genotypes were determined by the SNP chips (Illumina, 60K). The results showed that except that IMF and shear force (SF) heritability estimates were obviously different using the two methods, heritability estimates of the other traits were similar using the two methods. Furthermore excepted for tenderness, the heritabilities estimated using GBLUP were lower than those using BLUP method. All the carcass traits were of medium heritability except that the eviscerating percentage was of low heritability. The heritability estimates of tenderness were low, but the IMF using BLUP and GBLUP methods presented medium (h²=0.256) and low heritability (h²=0.107),respectively. Using BLUP, IMF showed high negative genetic correlations with BW, BMP and SF traits (-0.572, -0.420, -0.682), moderate negative genetic correlations with EP (-0.234), and moderate positive genetic correlations with AFP (0.420), respectively; using GBLUP, IMF showed high negative genetic correlations with BW, BMP and SF (-0.808, -0.725, -0.784), high negative genetic correlations with EP (-0.626), and low positive genetic correlations with AFP(0.097), respectively. In conclusion, there were large differences between estimates of genetic parameters for some traits using the traditional BLUP method and the new GBLUP method. In breeding practices, comprehensive consideration is needed to improve the breeding efficiency.

The aim of this study was to clone the alternative splicing isoforms of pig NR1H3 gene, to predict the structures and functions of their coding proteins, and to investigate the expression patterns of each transcript. The Mashen pig was used in this study. The full-length coding sequence (CDS) of NR1H3 gene in Mashen pig was cloned and sequenced, the biological characteristics of NR1H3 protein was analyzed by bioinformatics methods, and the expression patterns of NR1H3 gene in heart, liver, spleen, lung, kidney, stomach, small intestine, biceps femoris, psoas magnus and subcutaneous fat and the chronological expression trends in adipose tissue in Mashen pig were detected by quantitative real-time PCR (qRT-PCR). The results showed that two of the transcripts of NR1H3 gene, NR1H3-1 and NR1H3-2, were successfully obtained. NR1H3-2 was a new transcript (MN082630), and the length of CDS was 1 203 bp, which encoded 400 amino acids. The encoded protein was neutral unstable protein. Compared with the NR1H3-1 transcript, NR1H3-2 had a deletion of the 9th exon with a length of 95 bp. Coding protein NR1H3-2 had a deletion of ligand binding domain of liver X receptors compared with NR1H3-1. The similarity of NR1H3 amino acid sequence of pig to those of Balaenoptera acutorostrata scammoi, Capra hircus, Ovis aries, Physeter catodon, Neophocaena asiaeorientalis asiaeorientalis was higher. NR1H3-1 and NR1H3-2 were expressed in all detected tissues in this study, and the expression differences among different tissues were significant (P<0.05). The highest abundance of NR1H3-1 was in small intestine, followed by spleen, liver and biceps femoris, and the lowest expression level was in heart. The highest abundance of NR1H3-2 was in liver, followed by spleen, small intestine, stomach and biceps femoris, and the lowest expression level was in heart. The abundance of NR1H3-2 in all tissues except for small intestine, heart and lung were higher than that of NR1H3-1, and the expression difference between NR1H3-1 and NR1H3-2 was extremely significant in liver and subcutaneous adipose tissue (P<0.01), and the difference was significant in stomach (P<0.05). With the increase of age, the expressions of NR1H3-1 and NR1H3-2 in adipose tissue in Mashen pig showed an overall upward trend, which could be deduced that NR1H3 gene might play an important role in the regulation of fat deposition in pig. In this study, two transcripts of pig NR1H3 gene were successfully cloned. It was speculated that NR1H3 might play important physiological roles in lipid metabolism and fat deposition in pig.

In this study, in order to screen out the optimal meat sheep hybrid combination for suitable breeding in Tangshan area, Hebei Province, and to better guide production practices, three groups of meat sheep hybridization experiments were carried out, using AWF sheep, Dorper sheep and Charolais sheep as the male parent respectively, and the Small-tail Han sheep as the female parent. Among them, group 1 was the hybrid combination between AWF sheep and Small-tail Han sheep (AH group), group 2 was the hybrid combination between Dorper sheep and Small-tail Han sheep (DH group), and group 3 was the hybrid combination between Charolais sheep and Small-tail Han sheep (XH group). The growth performance and genetic effects of CLPG gene in hybrid progeny (F1) of 3 groups meat sheep were measured and analyzed. The results showed that under the same feeding conditions, birth weight of Xiahan ewes was slightly lower than that of Aohan ewes, the birth weight(ram), weaning weight, 6-month-old weight and average daily gain from birth to weaning of Xiahan hybrid progeny (F1) were the highest, and significantly or extremely significantly higher than those of the Duhan and Aoan hybrid progeny (F1) (P<0.05, P<0.01). The average daily gain from weaning to 6-month-old of Duhan hybrid progeny (F1 rams and ewes) were the highest, followed by Xiahan hybrid progeny (F1 rams and ewes), and the difference between Duhan hybrid progeny (F1 rams and ewes) and the other two groups was not significant(P>0.05). Except for body length and chest width at 3-month-old, and body length and body height at 6-month-old, the residual body size indexes of Xiahan hybrid progeny (F1) were the highest, and some of them were extremely significantly higher than those of Aohan hybrid progeny (F1) (P<0.01). The above results indicate that the Xiahan hybird progeny (F1) had a higher basic body weight and a faster growth rate after birth,while Duhan hybrid progeny (F1) showed a faster growth rate after weaning. The genetic effects analysis of CLPG gene showed that there was a missense mutation site at the 41 bp for 3 meat sheep hybrid progeny(F1) populations. There were CC and CT genotypes at this mutation site. The CC genotype was dominant genotype, and C allele was dominant allele. The least squares analysis of genotype and growth traits showed that birth weight, weaning weight, 6-month-old weight, 3-month-old body size indexes and 6-month-old body size indexes of individuals with CT genotype were significantly higher than those of individuals with CC genotypes. Based on the above results, it is suggested that the hybridization advantage between Charolais sheep and Small-tail Han sheep is obvious. T allele can promote the growth and development of meat sheep. It is recommended to choose the Xiahan hybrid combination and the individual carrying T allele when organizing meat sheep production in Tangshan area, Hebei Province.

The aim of this study was to clone the sequence of zinc finger domain of goat KLF2, to clarify the tissue and cell expression profiles of KLF2, and finally to elucidate the effect of interfering KLF2 gene on the goat intramuscular preadipocytes differentiation and the possible ways of action. In this study, 5 healthy, 1-year-old Jianzhou Big Ear goats were selected as experiment animals. By using RT-PCR, cell culture, real-time quantitative PCR (qPCR), RNA interference and other methods, the sequence of the zinc finger domain of goat KLF2 gene was cloned, the tissue and cell temporal expression of KLF2 gene was detected and futher the effect of KLF2 gene on goat intramuscular preadipocytes differentiation was elucidated. The results showed that the length of goat KLF2 zinc finger domain was 454 bp (KU041748.1), and the domain had 100% homology with sheep, cattle and mice. KLF2 was widely expressed in goat tissues with the higher expression level in the lung and abdominal fat (P<0.05). The expression of KLF2 decreased first, then increased, and decreased again during the intramuscular preadipocytes differentiation, the expression level reached to the lowest after differentiation 12 h, which was significantly lower than that in undifferentiated preadipocytes (P<0.05). Oil red O staining result showed that interfering KLF2 significantly promoted the accumulation of lipid droplets in adipocytes; and the expression of PPARγ and C/EBPβ were extremely significantly up-regulated by 48.5% (P<0.01) and significantly up-regulated by 43.6%(P<0.05); At the same time, the expression level of KLF1, KLF13, KLF14, KLF15 and KLF16 were extremely markedly increased (P<0.01), the expression level of KLF4 was significantly decreased (P<0.05), and the expression level of KLF3, KLF6, KLF8, KLF9 and KLF11 were extremely significantly decreased (P<0.01). The zinc finger domain of goat KLF2 was highly conserved with other species, and KLF2 was highly expressed in lung and abdominal fat of goat(P<0.05). Meanwhile, KLF2 was a negative regulator for goat intramuscular preadipocytes differentiation, and might play an important role through targeting PPARγ and C/EBPβ genes, what's more it could hierarchically regulated other KLFs members.

This study aimed to investigate the expression and function of WNT2 in ovine follicular granulosa cells (GCs). In this study, both ovaries of 20 healthy ewes aged 4-6 months were collected and the expression of WNT2 protein in follicles was localized by immunohistochemistry; qRT-PCR and Western blot were used to detect the differences of its expression in follicular granulosa cells at different developmental stages; The Wnt2 expression was silenced in GCs, and the relative expression of Wnt2 gene and the key gene CTNNB1 involved in the classical WNT signaling pathway were analyzed using qRT-PCR technology, and the apoptosis of GCs was detected. The results showed that:1) WNT2 protein was expressed in theca interna cells, granulosa cells and cumulus cells of ovine. 2) The results of qRT-PCR and Western blot were basically consistent, the expression of Wnt2 mRNA and protein in granulosa cells with different sizes were significantly different (P<0.05), and the expression in large follicle granulosa cell was significantly higher than that in medium follicles (P<0.05), and the expression in medium follicle granulosa cell was significantly higher than that in small follicles (P<0.05). 3) After silenced Wnt2 gene, the expressions of Wnt2 and CTNNB1 in Wnt2 siRNA group were significantly lower than those in nonsense sequence siRNA group (NC group) and blank control group (P<0.05), while the percentage of apoptosis in Wnt2 siRNA group was significantly higher than those in the other two groups(P<0.05). In conclusion, WNT2 can improve the biological function of ovaries granulosa cells in sheep by the WNT2/CTNNB1 signal pathway.

This study aimed to research factors affecting the efficiency of equine embryo transfer. The data of embryo transfer in 3 horse farms from 2013 to 2018 were analyzed.The number of donor horses in the 3 farms were 15, 21 and 25, respectively, and the number of recipient mares were 56, 50 and 75 respectively. All mares were 3 to 12 years old. The following items were counted:The effect of flushing day post ovulation of donor horses on the embryo recovery rate; The effect of embryonic age on the pregnancy rate of recipient mares after transplantation; The effect of the degree of ovulation synchronization of the donor and recipient mares on the pregnancy rate after transplantation; The effect of residence time at farm of recipient mares on pregnancy rate after transplantation. The results indicated that, mares were injected with prostaglandin (PG)+GnRH analogues or PG + hCG to induce ovulation during the breeding season, the estrous cycle were (14.5±0.8) and (14.3±1.1)d, respectively, which was significantly lower than the control group ((20.5±2.6) d, P<0.05). The embryo recovery rate of washing the uterus on the 8th day after ovulation was higher than that on the 7th day, but the difference was not significant; The pregnancy rate of recipient horses after 8-day-old embryo transfer was higher than that of 7-day-old, and the difference was not significant; After embryo tranfer, the recipients which ovulated 1 day later than donors had the highest pregnancy rate. When the residence time at farm of recipients was longer than 1 year, the pregnancy rate was significantly higher than those shorter than 0.5 year. In conclusion, the injection of PG + hCG or PG + GnRH anologue could shorten estrus cycle of mares. The embryo recovery rate and the pregnancy rate after transplantation of the 8th day embryo after ovulation were higher. When the embryos were transplanted, the mares with the residence time at farm more than 1 year and the ovulation time 1 day later than the donors were used as recipients.

This experiment was conducted to study the effect of feeding level on productive performance, organ development and body energy deposition of male Arctic foxes during the winter fur growth period. Forty-six healthy 161-day-old male Arctic foxes with average body weight of (7 285±5.77) g were selected, including 6 Arctic foxes as slaughter trial control at the beginning of the trial, another 40 Arctic foxes were randomly divided into 4 groups with 10 replicates per group and 1 fox per replicate. The foxes were offered diet for ad libitum (AL,Group I), 80% (IR80,Group II), 60% (IR60,Group III) and 40% (IR40,Group IV) of ad libitum intake, respectively. The experiment was 7 days for adaption and 67 days for trial period. The parameters of growth performance, fur quality, organ development and body energy deposition were evaluated by means of feeding, slaughter trials and chemical analysis methods. The results showed as follows:1) With the decrease of feeding level, ADFI showed an extremely significant decrease(P<0.01), ADG in group II was extremely significantly higher than that in group IV (P<0.01), and significantly higher than that in group III (P<0.05), and there was no significant difference between group II and I (P>0.05). Final weight (FW) and F/G were not significantly different among different groups(P>0.05), whereas the FW in group II were higher than those in the other groups, and F/G in group II were lower than those in the other groups. 2) Different feeding levels extremely significantly affected length of fresh pelt (P<0.01). Length of fresh pelt in group I was extremely significantly higher than those in group III and IV (P<0.01), and no significant difference was found between group I and II (P>0.05). With the decrease of feeding level, there were decreased trends in body length, length of dried pelt, length of guard hair and length of under hair, but there were no significant difference among 4 groups (P>0.05). 3) Different feeding levels significantly affected heart weight and heart index (P<0.05 or P<0.01). Heart weight in group II was significantly higher than that in group III (P<0.05), and no significant difference was found among group I, II and IV (P>0.05). Heart index in group IV was extremely significantly higher than that in group I (P<0.01), and significantly higher than that in group III (P<0.05), but no significant difference was found between group II and IV (P>0.05).Whereas feeding levels did not significantly affect the weight and indexes of liver, kidney, spleen, lung (P>0.05). 4)With the decrease of feeding level, there were all decreased trends in pelt weight gain, pelt fat deposition and its energy deposition, total pelt energy deposition, carcass fat deposition and its energy deposition, carcass protein deposition and its energy deposition as well as total carcass energy deposition, whereas there were no significant difference in all parameters of energy deposition of pelt and carcass among different groups(P>0.05). Feeding 80% of ad libitum intake (IR 80) does not affect the normal development of body organs, could ensure the body weight gain and fur quality, improve the feed efficiency and also reduce the obesity risk due to excessive energy deposition of Arctic foxes during the winter fur growth period.

To investigate the effect of betaine on lipid deposition and its potential mechanism in muscle tissue of mice with leptin deficiency (ob/ob), in this study, twelve 6-week-old healthy ob/ob male mice of the same batch were randomly divided into two groups:experimental group and control group. Their weight difference was less than 1 g. Mice in the control group drank purified water, and mice in the experimental group drank purified water containing 1% betaine. One month later, the mice were killed and muscle samples were collected. Then, lipid deposition in muscles was detected by oil red O staining and triglyceride detection, and fatty acids composition and content in muscles were analyzed by Meteorological Chromatography-Mass Spectrometry System. Also, qRT-PCR was used to measure gene expression levels in muscle. The results showed that,compared with control group:1) The weight gain, lipids deposition and fasting blood glucose were significantly reduced after ob/ob mice were treated with betaine(P<0.05). 2) Betaine supplementation caused the extremely significantly increase in the expression of hormone-sensitive lipase (HSL), adipose triacylglyceride lipase (ATGL) and glucose transpoter 4 (GLUT4) (P<0.01). 3) Betaine supplementation could significantly increase saturated fatty acids (SFA) and polyunsaturated fatty acids (PUFA) content in muscle tissues of ob/ob mice(P<0.05). 4) Betaine supplementation significantly down regulated the expression of fatty acids synthetase (FAS, P<0.05), and up regulated the expression of fatty acid oxidation genes such as peroxisome proliferator activated receptor alpha (PPARα), acyl-CoA oxidase2 (ACOX2), long chain acyl-CoA dehydrogenase (ACADL) and fatty acid transposase (CD36) in muscle of ob/ob mice(P<0.01), while no significant difference was observed in acetyl-CoA synthetase (ACS) expression levels between experimental group and control group(P>0.05). When ob/ob mice were supplemented with betaine for one month, the expression of fatty acid synthesis gene in muscle tissue decreased, the expression of fatty acid oxidation gene increased, and the fatty acid content of muscle tissue changed, which eventually led to the decrease of muscle tissue lipid.

Recently, two novel subgroups of porcine epidemic diarrhea virus (PEDV) were identified in Tibetan pigs on the Qinghai-Tibet Plateau. We further investigated if the novel variant PEDV exists or had been prevalent in Sichuan region. One hundred and sixteen fecal and intestinal tissue samples collected in 2018-2019 from diarrheal pigs of Sichuan were detected for PEDV by RT-PCR, and the molecular characteristics of Spike genes (S) of PEDV were further investigated in this study. The results showed that the detection rate of PEDV was 42.2% (49/116, 95%CI=33.1%-51.8%) in diarrhea samples. Thirteen complete S gene sequences were obtained, and they were 4 149-4 170 bp in length, sharing 94.2%-99.9% identities with each other. Interestingly, SWUN-H3-CH-SCYA-2019 shared 97.0%-98.6% nucleotide sequence identities with those of the novel G1 subgroup of Tibetan Pig PEDVs. Phylogenetic and evolutionary analysis showed that the 13 S genes obtained in this study could be divided into G1 and G2 subgroups, one of which (SWUN-H3-CH-SCYA-2019 strain) fell into the novel G1 subgroup of Tibetan Pig PEDVs; the SWUN-19-CH-SCZY-2018, SWUN-4-CH-SCXC-2018, SWUN-1-CH-SCNJ-2019 and SWUN-3CH-CH-SCZG-2019 were clustered into an unique branch of G2 subgroup, and shared high sequence identities with the novel G2 subgroup of Tibetan Pig PEDVs. To further study the evolution process of 13 PEDVs, the BEAST software was used to estimate the divergence time. The results showed that the divergence time of SWUN-H3-CH-SCYA-2019 was about 2012.3 year, earlier than the earliest divergence time of the other novel G1 subgroup strains (2015.7 year), and the divergence time of SWUN-4-CH-SCXC-2018, SWUN-19-CH-SCZY-2018 and SWUN-3CH-CH-SCZG-2019 were about 2014.2 year, earlier than that of the novel G2 subgroup (2014.7 year). The divergence time of Tibetan pig PEDVs was later than that of strains identified in this study. Tibetan Pig PEDVs were first detected in Sichuan region, and we deduced a conclusion from different divergence time that the novel Tibetan Pig PEDVs were originated from Sichuan region. This study will provide the theoretical basis for monitoring the new variation of PEDV.

This study aimed to achieve the effective secretory expression of E2 of classical swine fever virus (CSFV) using baculovirus by introducing the signal peptide. Firstly, the pFastBac1 vector was modified by adding the endogenous E2 signal peptide, the melittin signal peptide or the gp67 signal peptide, respectively. Then the E2 gene fragment was cloned into the modified vectors. The resulting plasmids were then transformed into the DH10Bac competent cells to get recombinant bacmids through blue-white screening. The bacmids were subsequently transfected into the sf21 cells to generate recombinant baculoviruses. Secondly, the sf21 cells were infected for large-scale protein production. The E2 protein was purified by nickel-affinity chromatography and the purity was identified using SDS-PAGE. Finally, the glycosylation pattern and the immunogenicity of the purified E2 were analyzed. Results were as follows:Consequently, the recombinant plasmids were generated. The recombinant bacmids were acquired through blue-white screening. The Western blot analysis showed that the secretory expression of E2 was achieved by introducing signal peptides. Among the three signal peptides, the gp67 mediated the highest secretion efficiency. It was shown that the E2 protein was pure and the yield was about 25 mg·L^-1. Indirect ELISA results demonstrated that the purified E2 protein could be specifically recognized by the CSFV positive serum, indicating that the purified E2 protein was immunogenic. The purified E2 protein was used to immunize BALB/c mice after emulsification with ISA201 adjuvant. The blocking ELISA result showed that the antibody could be detected after 14 days of immunization, indicating that the E2 protein had good immunogenicity. Taken together, the study is useful for developing a subunit vaccine against CSFV using the E2 expressed in the sf21 cells.

The aim of this study is to investigate the characteristics and changes of bacterial flora in midguts of Dermacentor nuttalli and Dermacentor silvarum with the extension of feeding time. The half or fully engorged D. nuttalli and D. silvarum were obtained from sheep body surface in Hulun Buir of Inner Mongolia and Guyuan of Ningxia, respectively. The midgut contents were collected from ticks under sterile environment. Then the total DNA of bacteria were extracted and the V3-V4 areas of 16S rDNA were amplified. The PCR product of each sample was sequenced by IonS5^TMXL high-throughput sequencing platform. Each sample's bacterial flora characteristic and the differences among four groups (half engorged D.nuttalli, fully engorged D.nuttalli,half engorged D.silvarum and fully engorged D.silvarum) were analyzed. The results showed that the bacterial diversity of midguts from the half engorged D. silvarum was the highest, followed by that of midguts from half and fully engorged D. nuttalli, the bacterial diversity of midguts from the fully engorged D. silvarum was the lowest. Proteobacteria was the most predominant phyla in all samples. Anaplasma, Rickettsia, Stenotrophomonas and Coxiella were the major genera. The relative abundance of Anaplasma in midguts from fully engorged D. nuttalli and D. silvarum were higher than that in the midguts from the half engorged ticks. The relative abundance of Rickettsia and Coxiella in midguts from half engorged D. nuttalli and D. silvarum were higher than that in the midguts from the fully engorged ticks. Anaplasma marginale, Pseudomonas geniculate and Coxiellaceae bacterium RFE02 were the most predominant species in four samples. Distributions of A. marginale in the midguts of D. nuttalli and D. silvarum were consistent with that of Anaplasma. These findings suggested that the midgut bacterial flora of D. nuttalli and D. silvarum are susceptible to the blood-sucking behavior. The relative abundance of common bacteria genera and species vary greatly in different tick species and engorged statuses.

miRNAs are important factors in the regulation of breast tissue development and lactation function. In this study, according to existing miRNA expression profiles of breast tissues in different lactation stages of guanzhong dairy goats, miR-92a expressed differently in different lactation periods was taken as the research object to study the regulatory effect of miR-92a on the proliferation and apoptosis of goat mammary epithelial cells(GMEC),and explore its pontential regulatory genes. The expression of miR-92a in breast tissues at different lactation stages was detected by fluorescence quantitative PCR, MTT assay, EdU assay and flow cytometry, and the regulatory effect of miR-92a on the proliferation and apoptosis of GMECs and cell cycle was detected at the cell level. RNA-seq was used to analyze the differentially expressed genes in GMECs overexpressing miR-92a. qRT-PCR results showed that the expression level of miR-92a in breast tissues of dairy goats in the early lactation stage was significantly higher than that in the middle lactation stage (P<0.01), suggesting that miR-92a may play an important role in regulating lactation traits of dairy goats. After miR-92a was overexpressed in GMEC, the test results showed that compared with the NC group, the number of EdU positive cells in the miR-92a overexpressed group was significantly reduced (P<0.01), the number of cells in the S phase was significantly decreased, and the number of cells in the G1 phase was significantly increased, while the number of apoptotic cells in the miR-92a group was significantly increased (P<0.05).Transcriptome sequencing technology constructed the mRNA library of miR-92a overexpression, and found 54 genes were down-regulated, meanwhile 160 genes were up-regulated. Analysis of GO terms and KEGG pathway showed that differentially expressed genes involved in regulating various biological functions of mammary epithelial cells. The above results indicate that miR-92a promotes the apoptosis of mammary epithelial cells and inhibits cells proliferation. The sequencing results further prove that miR-92a plays an important role in the regulation of breast development and lactation performance in dairy goats.

This study was conducted to investigate the molecular mechanism of bta-miR-677 regulating the expression of type Ⅰ interferon (IFN). Bta-miR-677 was transfected into MDBK cells to detect the transcription level of type Ⅰ IFN and interferon stimulating genes (ISGs). Then we predicted the target gene of bta-miR-677 by TargetScan, and the target gene of bta-miR-677 was verified by dual-luciferase report gene system, qRT-PCR and Western blot assay. The effect of the target gene on IFN transcription was verified by siRNA knockdown. The results showed that the transcription of IFN-α/β in bta-miR-677 group were 2-4 times higher than that of the control group (P<0.001), moreover, the transcription of six ISGs(IFI6, OAS1Y, OAS1Z, RSAD2, MX1 and MX2) were up-regulated by 2-16 times (P<0.01 or P<0.001). By contrast, the transcription of IFN-α/β in bta-miR-677 inhibitor group were down-regulated (P<0.01 or P<0.05), then the transcription of IFI6, OAS1Y, OAS1Z, RSAD2, MX1 and MX2 were down-regulated (P<0.05 or P<0.01). Subsequently, we demonstrated that bta-miR-677 could target the 3'-UTR of MAVS (mitochondria antiviral signaling protein) and the expression of MAVS is inhibited. Meanwhile, silencing of MAVS up-regulated the expression of IFN-α/β and the six ISGs. The results showed that bta-miR-677 up-regulated the transcription level of IFN-α/β by targeting MAVS, and then increased the transcription of ISGs. This study reveals that bta-miR-677 up-regulated type Ⅰ IFN by targeting MAVS to increase the expression of ISGs, which provided important data for the development of antiviral drugs based on bta-miR-677.

The aim of this study was to establish a simple and reliable assay for fluorescence labeling Muscovy duck lymphoeytes and then analyze the effects of Muscovy duck reovirus (MDRV) infection on lymphocytes homing of ileum in Muscovy ducklings. 5(6)-carboxydiacetate fluorescein succinimidyl ester (CFDA-SE, CFSE), a living cell fluorescent reagent, was used to label the peripheral blood lymphocytes of Muscovy ducklings. Flow cytometry was used to detect and analyze the lymphocytes that marked in vitro and traced in vivo. In addition, CFSE⁺ lymphocytes of ileum in MDRV-infected and uninfected Muscovy duck were detected and analyzed by flow cytometry and paraffin section immunofluorescence. Results were as follows:The optimal conditions of labeling lymphocytes by CFSE were PBS as the incubation solution, 10 μmol·L^-1 CFSE, 37℃ and 30 min, respectively. The labeled lymphocytes were injected into the Muscovy duck through the brachial vein, the CFSE⁺ lymphocytes in the peripheral blood were basically stable at 2% to 5%. The order of sequence of peak of CFSE⁺ lymphocytes was spleen, jejunum, ileum, cecum, duodenum, bursa and thymus. CFSE-labeled lymphocytes were injected into brachial veins of the young Muscovy ducks before MDRV infection, and the rate of CFSE⁺ lymphocytes in MDRV group was significantly (P<0.01) higher than that in the MOCK group at 1-10 days post infection. This result was consistent with tests of α4⁺ lymphocytes and paraffin section fluorescence. Overall, these results showed that the CFSE-labeling lymphocytes can be used for lymphocytes trace in vivo, and preliminary application results revealed that MDRV infection promotes the lymphocyte homing of ileum in Muscovy ducklings, which provide a basis for further studying the intestine pathogenic mechanism of MDRV infection.

This experiment was aimed to use the magnetic resonance imaging to study the anatomical structure of Hu-sheep's brain. Ten healthy Hu-sheep were scanned by a 1.5 T magnetic resonance scanner. Sagittal, transverse and dorsal aspect images of the brain were archived by using three sequences which are spin echo (SE), fast spin echo (FSE), and fluid attenuated inversion recovery (FLAIR). All anatomical structure of MR images were noted, the height of diencephalon, cerebrum, telencephalon, the third ventricle, the fourth ventricle were measured,the same as the pituitary gland's height, length and width. As a result, we have established a complete image atlas and provided basic imaging data of the normal Hu-sheep's brain structure. It can provide helpful informations for imaging diagnosis of Hu-sheep's and the other sheep's brain disease, as well as provide a valuable reference for medical experimental animal model.

In order to increase the porosity of the meniscus acellular matrix (MAM) scaffolds and improve the amount of cells implanted in them, canine menisci were drilled firstly and then decellularized in this experiment. Next, the decellularization effect and changes in porosity and mechanical properties of the scaffolds were detected. The amount of cells implanted and expression of glycosaminoglycan and type Ⅱ collagen in the scaffolds were examined after chondrogenic induction with BMSCs (bone marrow mesenchymal stem cells). The results showed that the decellularization effect of the drilled scaffold was good, no nuclei were found, and the collagen fibers were structurally intact. The porosity of the scaffold was significantly increased, but the compressive modulus did not change significantly. The amount of BMSCs implanted in the drill scaffold was significantly increased. The rate of cell proliferation and the ability to differentiate into cartilage were significantly improved. The results indicated that the drilling method used can increase the porosity of the meniscus matrix scaffold, which not only maintains the mechanical properties of the scaffold and increases the amount of cells implanted, but also promotes cell proliferation, differentiation and tissue remodeling. It laid a foundation for the wide application of MAM scaffolds in tissue engineering meniscus construction.

A rare case of feline ovarian malignant granulosa cell tumor with abdominal implantable metastasis is reported in this article. It has not been reported in literature. A 15-years old female cat was treated for loss of appetite and abdomen enlargement. Ultrasound examination revealed a tumor of approximately 4.27×2.63 cm in size on the left renal tail. A large number of spherical masses of varying sizes were distributed on large omentum, intestinal wall and stomach wall. The left ovary was significantly enlarged, and solid or soft nodules were on the surface. The tumor was diagnosed as ovarian malignant granulosa cell tumor through histological examination. This article provides clinical and histopathological data of this case, and review of relevant literature. The authors hope to help with the diagnosis and research of this tumor.

The aim of this study was to investigate the expression level of miR-502 and its clinical significance in canine breast cancer tissues. A total of 30 cases of canine breast cancer tissues and normal adjacent tissues were enrolled in this study. The expression levels of miR-502 were detected by real-time quantitative polymerase chain reaction (qRT-PCR). The relationship between the levels of miR-502 and the clinicopathological features (age, tumor size, histological grade and metastasis state) of canine breast cancer were analyzed. The experiment results showed that compared with the adjacent normal tissues, the levels of miR-502 transcription in canine breast cancer tissues increased significantly (P<0.01). The transcription of miR-502 was related with histological grade and metastasis in canine breast cancer (P<0.05); but not related with tumor size or age (P>0.05). The miR-502 transcription level is up-regulated in canine breast cancer that related with tumorigenesis and progression of canine breast cancer. miR-502 can be used as a tumor marker for diagnosis prediction of canine breast cancer.

Scientific funding resource is of great importance for the animal husbandry and veterinary medicine innovation as well as for the industry development. During the 13th Five-Year Period, the "National Key Research and Development Program" special project named "Prevention and control of major animal diseases, efficient and safe husbandry technology research and development" has been initiated. Research fields including animal diseases prevention and control, efficient and safe husbandry, husbandry environment control and husbandry equipment development were taken into consideration and supported through this special project. According to research differences, projects ranging from fundamental research, key technology development to technical integration and demonstration were designed and implemented. In this review, we introduced and analyzed Research and Development arrangement profiles of this special program, and also other national key Research and Development programs in animal husbandry and veterinary medicine fields during the 13^th Five-Year Period, perspectives were also provided for the future development of this field.