Small Tail Han Research Articles

Functional analysis of microorganisms and metabolites in the cecum of different sheep populations and their effects on production traits.

The purpose of this study was to investigate the effects of intestinal microbiota on the growth and production performance of different groups of sheep, focusing on the role of cecal microbiota in regulating intestinal function, enhancing digestion and absorption, and improving feed utilization. The production performance of MG × STH (Mongolia × Small Tailed Han) F1 hybrids and purebred STH (Small Tailed Han) sheep by measuring various factors, including enzyme activities and VFAs (volatile fatty acids), to analyze changes in cecal fermentation parameters across different sheep groups. Metagenomic and metabolomic sequencing combined with bioinformatics to analyze the cecal contents of the two sheep populations. The study findings indicated that the MG × STH F1 hybrids outperformed the purebred STH in terms of body weight, height, oblique body length, and VFAs (p < 0.05). Additionally, the MG × STH F1 higher levels of protease and cellulase in the cecum compared to the purebred sheep (p < 0.05). Metagenomic analysis identified 4,034 different microorganisms at the species level. Five differential organisms (Akkermansiaceae bacterium, Escherichia coli, unclassified p Firmicutes, Streptococcus equinus, Methanobrevibacter millerae) positively regulated sheep performance. Metabolomics identified 822 differential metabolites indoleacetaldehyde, 2-aminobenzoic acid, phenyl-Alanine, enol-phenylpyruvate and n-acetylserotonin were associated with improved performance of sheep. The combined results from the metagenomic and metabolomic studies suggest a positive correlation between specific microbes and metabolites and the performance of the sheep. In conclusion, the MG × STH F1 hybrids demonstrated superior growth performance compared to the purebred STH sheep. The identified microorganisms and metabolites have promising roles in positively regulating sheep growth and can be considered key targets for enhancing sheep performance.

Analysis of the Long Non-Coding and Messenger RNA Expression Profiles in the Skin Tissue of Super Merino and Small-Tailed Han Sheep.

Wool quality and yield are two important economic livestock traits. However, there are relatively few molecular studies on lncRNA for improving sheep wool, so these require further exploration. In this study, we examined skin tissue from the upper scapula of Super Merino (SM) and Small-Tailed Han (STH) sheep during the growing period. The apparent difference was verified via histological examination. High-throughput RNA sequencing identified differentially expressed (DE) long non-coding (lncRNAs) and messenger RNAs (mRNAs). The target gene of DE lncRNA and DE genes were enrichment analyzed using Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG). A Reverse Transcription quantitative Polymerase Chain Reaction (RT-qPCR) was used to verify randomly selected DE lncRNAs and mRNAs. Finally, the DE, RAC2, WNT11, and FZD2 genes, which were enriched in the Wnt signaling pathway, were detected via immunohistochemistry. The results showed that a total of 20,888 lncRNAs and 31,579 mRNAs were identified in the skin tissues of the two sheep species. Among these, 56 lncRNAs and 616 mRNAs were differentially expressed. Through qRT-PCR, the trends in the randomly selected DE genes' expression were confirmed to be aligned with the RNA-seq results. GO and KEGG enrichment analysis showed that DE lncRNA target genes were enriched in GO terms as represented by epidermal and skin development and keratin filature and in KEGG terms as represented by PI3K-Akt, Ras, MAPK, and Wnt signaling pathways, which were related to hair follicle growth and development. Finally, immunohistochemistry staining results indicated that RAC2, WNT11, and FZD2 were expressed in dermal papilla (DP). The lncRNAs MSTRG.9225.1 and MSTRG.98769.1 may indirectly participate in the regulation of hair follicle growth, development, and fiber traits by regulating their respective target genes, LOC114113396(KRTAP15-1), FGF1, and IGF1. In addition, MSTRG.84658.1 may regulate the Wnt signaling pathway involved in the development of sheep hair follicles by targeting RAC2. This study provides a theoretical reference for improving sheep breeding in the future and lays a foundation for further research on the effects of MSTRG.84658.1 and the target gene RAC2 on dermal papilla cells (DPC).

Single-cell RNA-seq reveals the effects of the FecB mutation on the transcriptome profile in ovine cumulus cells

Genetic variations in the ovine ovulation rate, which are associated with the FecB mutation, provide useful models by which to explore the mechanisms regulating the development of mammalian antral follicles. In order to study the effects of the FecB mutation on cumulus cell differentiation, preovulatory follicles were aspirated and cumulus cells were isolated from three FecB genotypes (homozygous, heterozygous and wild type) of Small Tail Han (STH) sheep superstimulated with FSH. Transcriptome information from tens of thousands of cumulus cells was determined with the 10 × Genomics single-cell RNA-seq technology. Under the superovulation treatment, the observed number of preovulatory follicles in the ovaries of FecB carriers was still significantly higher than that in the wild-type (P < 0.05). The expression patterns of cumulus cells differed between FecB carriers and wild-type ewes. The screened cumulus cells could also be further divided into different cell clusters, and the differentiation states and fates of each group of cumulus cells also remained different, which supports the notion that heterogeneity in gene expression is prevalent in single cells. The oxidative phosphorylation pathway was significantly enriched in differentially expressed genes among the cell differentiation branch nodes of cumulus cells and among the differentially expressed genes of cumulus cells from the three genotypes. Combined with the important role of oxidative phosphorylation in the maturation of COCs, we suggest that the oxidative phosphorylation pathway of cumulus cells plays a crucial role in the differentiation process of cumulus cells and the mutation effect of the FecB gene.

Key mRNAs and lncRNAs of pituitary that affect the reproduction of FecB + + small tail han sheep

BackgroundThe pituitary directly regulates the reproductive process through follicle-stimulating hormone (FSH) and luteinizing hormone (LH). Transcriptomic research on the pituitaries of ewes with different FecB (fecundity Booroola) genotypes has shown that some key genes and lncRNAs play an important role in pituitary function and sheep fecundity. Our previous study found that ewes with FecB + + genotypes (without FecB mutation) still had individuals with more than one offspring per birth. It is hoped to analyze this phenomenon from the perspective of the pituitary transcriptome.ResultsThe 12 Small Tail Han Sheep were equally divided into polytocous sheep in the follicular phase (PF), polytocous sheep in the luteal phase (PL), monotocous sheep in the follicular phase (MF), and monotocous sheep in the luteal phase (ML). Pituitary tissues were collected after estrus synchronous treatment for transcriptomic analysis. A total of 384 differentially expressed genes (DEGs) (182 in PF vs. MF and 202 in PL vs. ML) and 844 differentially expressed lncRNAs (DELs) (427 in PF vs. MF and 417 in PL vs. ML) were obtained from the polytocous-monotocous comparison groups in the two phases. Functional enrichment analysis showed that the DEGs in the two phases were enriched in signaling pathways known to play an important role in sheep fecundity, such as calcium ion binding and cAMP signaling pathways. A total of 1322 target relationship pairs (551 pairs in PF vs. MF and 771 pairs in PL vs. ML) were obtained for the target genes prediction of DELs, of which 29 DEL-DEG target relationship pairs (nine pairs in PF vs. MF and twenty pairs in PL vs. ML). In addition, the competing endogenous RNA (ceRNA) networks were constructed to explore the regulatory relationships of DEGs, and some important regulatory relationship pairs were obtained.ConclusionAccording to the analysis results, we hypothesized that the pituitary first receives steroid hormone signals from the ovary and uterus and that VAV3 (Vav Guanine Nucleotide Exchange Factor 3), GABRG1 (Gamma-Aminobutyric Acid A Receptor, Gamma 1), and FNDC1 (Fibronectin Type III Domain Containing 1) played an important role in this process. Subsequently, the reproductive process was regulated by gonadotropins, and IGFBP1 (Insulin-like Growth Factor Binding Protein 1) was directly involved in this process, ultimately affecting litter size. In addition, TGIF1 (Transforming Growth Factor-Beta-Induced Factor 1) and TMEFF2 (Transmembrane Protein With EGF Like And Two Follistatin Like Domains 2) compensated for the effect of the FecB mutation and function by acting on TGF-β/SMAD signaling pathway, an important pathway for sheep reproduction. These results provided a reference for understanding the mechanism of multiple births in Small Tail Han Sheep without FecB mutation.

Thyroid transcriptomic profiling reveals the differential regulation of lncRNA and mRNA related to prolificacy in small tail han sheep with FecB BB genotype

Background The thyroid gland is an important endocrine gland in animals that secretes thyroid hormones and acts on various organs throughout the body. lncRNAs are long non-coding RNAs that play an important role in animal reproduction; however, there is a lack of understanding of their expression patterns and potential roles in the thyroid gland of the Small Tail Han (STH) sheep. In this study, we used RNA-Seq technology to examine the transcriptome expression pattern of the thyroid from the luteal phase (LP) and follicular phase (FP) of FecB BB (MM) STH sheep. Results We identified a total of 122 and 1287 differential expression lncRNAs (DELs) and differential expression mRNAs (DEGs), respectively, which were significantly differentially expressed. These DELs target genes and DEGs can be enriched in several signalling pathways related to the animal reproduction process. Conclusions The expression profiles of DELs and DEGs in thyroid glands provide a more comprehensive resource for elucidating the reproductive regulatory mechanisms of STH sheep.

The comparison of meat yield, quality, and flavor between small-tailed Han sheep and two crossbred sheep and the verification of related candidate genes.

In Northeast China, Dorper and Australian White rams are commonly crossbred with small-tailed Han (STH) ewes to improve the offspring's meat yield and quality. However, the differences in traits and the flavor between the crossbred sheep and STH sheep remain unclear. In addition, the candidate genes potentially influencing the meat quality in the three sheep breeds require further verification. A total of 18 2-month-old healthy rams were raised over a period of 5 months, which included 6 STH, 6 Dorper and small-tailed Han crossbred (Do × STH), and 6 Australian white and small-tailed Han crossbred (Au × STH) offspring. The differences in slaughter, meat quality traits, fatty acid and amino acid composition in the muscular longissimus dorsi (MLD), and volatile compounds in the semitendinosus muscle were compared between the sheep breeds. The candidate genes related to intramuscular fat (IMF) content and fatty acids were validated. The results of this study revealed that the crossbred sheep had higher body weight, carcass weight, bone weight, net meat weight, and IMF content than the STH sheep (p < 0.05). The Do × STH offspring had a higher pH value (24 h), moisture content, and cooking percentage; they also had redder and brighter meat color. The content of myristate, palmitic, and margaric acids in the crossbred sheep was higher than that in the STH sheep (p < 0.05). The Do × STH offspring had the highest saturated fatty acid content (p < 0.05). The Au × STH offspring had the highest protein content (p < 0.05). The arachidonic acid and amino acid (Asp, Ala, Ile, Leu, Lys, Thr, and essential amino acid) contents were higher in the STH sheep than in the crossbred sheep (p < 0.05). The odor activity value (OAV) analysis showed that most of the aldehydes in the Au × STH offspring had higher values. The PDK4 gene expression was positively associated with the IMF content and was negatively correlated with the linoleic acid content in the Do × STH sheep (p < 0.05). The TMEM273 gene expression was positively associated with linoleic and arachidonic acid contents and was negatively correlated with oleic and palmitic acid contents in the Do × STH sheep (p < 0.05). The results showed the differences between the crossbred sheep and STH sheep and provided the candidate genes related to meat quality in sheep.

Expression profiles of oviductal mRNAs and lncRNAs in the follicular phase and luteal phase of sheep (Ovis aries) with 2 fecundity gene (FecB) genotypes.

FecB (also known as BMPR1B) is a crucial gene in sheep reproduction, which has a mutation (A746G) that was found to increase the ovulation rate and litter size. The FecB mutation is associated with reproductive endocrinology, such mutation can control external estrous characteristics and affect follicle-stimulating hormone during the estrous cycle. Previous researches showed that the FecB mutation can regulate the transcriptomic profiles in the reproductive-related tissues including hypothalamus, pituitary, and ovary during the estrous cycle of small-tailed Han (STH) sheep. However, little research has been reported on the correlation between FecB mutation and the estrous cycle in STH sheep oviduct. To investigate the coding and noncoding transcriptomic profiles involved in the estrous cycle and FecB in the sheep oviduct, RNA sequencing was performed to analyze the transcriptomic profiles of mRNAs and long noncoding RNAs (lncRNAs) in the oviduct during the estrous cycle of STH sheep with mutant (FecBBB) and wild-type (FecB++) genotypes. In total, 21,863 lncRNAs and 43,674 mRNAs were screened, the results showed that mRNAs had significantly higher expression levels than the lncRNAs, and the expression levels of these screened transcripts were lower in the follicular phase than they were in the luteal phase. Among them, the oviductal glycoprotein gene (OVGP1) had the highest expression level. In the comparison between the follicular and luteal phases, 57 differentially expressed (DE) lncRNAs and 637 DE mRNAs were detected, including FSTL5 mRNA and LNC_016628 lncRNA. In the comparison between the FecBBB and FecB++ genotypes, 26 DE lncRNAs and 421 DE mRNAs were detected, including EEF1D mRNA and LNC_006270 lncRNA. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes functional enrichment analysis indicated that the DE mRNAs were enriched mainly in terms related to reproduction such as the tight junction, SAGA complex, ATP-binding cassette, nestin, and Hippo signaling pathway. The interaction network between DE lncRNAs and DE mRNAs indicated that LNC_018420 may be the key regulator in sheep oviduct. Together, our results can provide novel insights into the oviductal transcriptomic function against a FecB mutation background in sheep reproduction.

Thyroid Transcriptomics Revealed the Reproductive Regulation of miRNA in the Follicular and Luteal Phases in Small-Tail Han Sheep with Different FecB Genotypes.

MicroRNA (miRNA) is a type of endogenous short-stranded ncRNA that influences many biological processes such as animal growth, development and metabolism. The thyroid gland is an important endocrine gland in sheep, and an increasing number of studies have shown that the thyroid gland plays an important role in animal reproduction, but the molecular mechanisms of the thyroid gland in sheep reproduction are poorly understood. In this study, RNA-seq was used to detect transcriptome expression patterns in the thyroid gland between the follicular phase (FP) and luteal phase (LP) in FecB BB (MM) and FecB ++ (ww) small-tail Han (STH) sheep, respectively, and to identify differentially expressed miRNAs (DEMs) associated with reproduction. Bioinformatic analysis of the target genes of these DEMs revealed that they can be enriched in multiple GO terms associated with the reproductive process in animals and in the KEGG signaling pathway. The miRNA-mRNA coexpression network revealed that oar-miR-133 and oar-miR-370-3p may play an important role in sheep reproduction. The results of the dual-luciferase reporter assay suggest a possible targeting relationship between novel-51 and TARBP2. These results provided a novel resource for elucidating regulatory mechanisms underlying STH sheep prolificacy.

Thyroid transcriptomic profiling reveals the differential regulation of lncRNA and mRNA related to prolificacy in Small Tail Han sheep with FecB++ genotype

The thyroid gland is an important endocrine gland in animals, which mainly secretes thyroid hormones and acts on various organs of the body. Long-chain non-coding RNA (lncRNA) plays an important role in animal reproduction. However, there is still a lack of understanding of their expression patterns and potential roles in the thyroid of Small Tail Han (STH) sheep. In this study, RNA-seq was used to examine the transcriptome expression patterns of lncRNAs and mRNAs in the follicular phase (ww_FT) and luteal phase (ww_LT) in FecB++ genotype STH Sheep. A total of 17,217 lncRNAs and 39,112 mRNAs were identified including 96 differentially expressed lncRNAs (DELs) and 1054 differentially expressed mRNAs (DEGs). Functional analysis of genes with significant differences in expression level showed that these genes could be enriched in Ras signalling pathway, hedgehog (HH) signalling pathway, ATP-binding cassette (ABC) transporters and other signalling pathways related to animal reproduction. In addition, through correlation analysis for lncRNA–mRNA co-expression and network construction, we found that LNC_009115 and LNC_005796 trans target NIK-related kinase (NRK) and poly(A)-specific ribonuclease (PARN). LNC_007189 and LNC_002045 trans target progesterone-induced blocking factor 1 (PIBF1), LNC_009013 trans targets small mothers against decapentaplegic (SMAD1) are related to animal reproduction. These genes add new resources for elucidating the regulatory mechanisms of reproduction in sheep with different reproductive cycles of the FecB++ genotype STH sheep.

Comparative proteomics of ovaries elucidated the potential targets related to ovine prolificacy.

Small Tail Han (STH) sheep, a unique Chinese breed, is recognized for its early maturity, year-round estrus, and prolificacy. However, the molecular mechanism of its high prolificacy has not been fully elucidated. The Proteomics approach is feasible and effective to reveal the proteins involved in the complex physiological processes of any organism. Given this, we performed the protein expression profiling of ovarian tissues during the luteal phase using polytocous STH sheep (litter size ≥2, three consecutive lambings) and monotocous STH sheep (litter size =1, three consecutive lambings) (PL vs. ML), and the follicular phase using polytocous STH sheep (litter size ≥2, three consecutive lambings) and monotocous STH sheep (litter size =1, three consecutive lambings) (PF vs. MF), respectively. Parallel Reaction Monitoring (PRM) was conducted to validate the differentially abundant proteins (DAPs). The tandem mass tag (TMT) quantitative proteomic results showed that a total of 5,237 proteins were identified, of which 49 and 44 showed differential abundance in the PL vs. ML and PF vs. MF groups, respectively. Enrichments analyses indicated that the DAPs including TIA1 cytotoxic granule-associated RNA-binding protein-like 1 (TIAL1), nicotinamide phosphoribosyltransferase (NAMPT), and cellular retinoic acid-binding protein 1 (CRABP1) were enriched at the luteal phase, while TIAL1, inhibin beta-a-subunit (A2ICA4), and W5PG55 were enriched at the follicular phase, potentially mediating reproductive processes in polytocous ewes. Furthermore, six DAPs were verified using PRM, confirming the accuracy of the TMT data acquired in this study. Together, our work expanded the database of indigenous sheep breeds and provided new ovarian candidate molecular targets, which will help in the study of the genetic mechanisms of ovine prolificacy.

Comparison of alternative splicing (AS) events in adipose tissue of polled dorset versus small tail han sheep

BackgroundDuring the alternative splicing (AS), the exons of primary transcripts are spliced in various arrangements, resulting in structurally and functionally distinct mRNAs and proteins. This study aimed to examine genes with AS events from Small Tail Han sheep and Dorset sheep to explore the mechanism of adipose developments. MethodsThis study identified the genes with AS events in adipose tissues of two different sheep with next-generation sequencing. In this paper, genes with significantly different AS events were performed gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. Results364 genes with 411 A S events showed significant differences in adipose tissues between the two breeds; 108 genes with 120 A S events were extremely significant differences between the two breeds. We identified several novel genes that are related with adipose growth and development. The results of KEGG and GO analysis indicated that oocyte meiosis, mitogen-activated protein kinase (Wnt), mitogen-activated protein kinase (MAPK) signaling pathway, etc. Were closely related to the adipose tissue developments. ConclusionsThis paper revealed that the genes with AS events are important for adipose tissues in sheep, exploring the mechanisms of AS events associated with adipose tissue developments in sheep of different breeds.

MiR136 regulates proliferation and differentiation of small tail han sheep preadipocytes

ABSTRACT Low meat performance is the defect of Small Tail Han sheep. Intramuscular fat affects meat quality and largely determined by adipogenesis. In previous study, miR136 was showed one of differentially expressed microRNAs between preadipocytes and mature adipocytes of Small Tail Han sheep but its role in adipogenesis is still not elucidated. Here, we investigated the effect of miR136 on adipogenesis and the underlying mechanism. qPCR data showed that miR136 level increased with preadipocytes proliferation while declined with preadipocytes differentiation. Moreover, miR136 mimics blocked lipid droplet formation, reduced lipid content and triglyceride accumulation while miR136 inhibitor showed the opposite effects, revealing that miR136 promoted preadipocytes proliferation but inhibited preadipocytes differentiation. Bioinformatics and biochemical validation manifested that PPARGC1B was a target of miR136. Furthermore, miR136 mimics decreased PPARγ and C/EBPα expression accompanied by PPARGC1B expression descending. Reverse effects were observed with miR136 inhibitor. Besides, overexpression of miR136 elevated IGF1 expression. Collectively, our data first exhibited a regulatory role of miR136 in adipogenesis, which is promoting preadipocytes proliferation through elevating IGF1 expression while inhibiting preadipocytes differentiation through targeting PPARGC1B and further declined PPARγ and C/EBPα expression. The modulation of PPARGC1B by miR136 may provide a new potential target for increasing intramuscular fat.

Effects of lamb sex and ewe parity on suckling-related neonatal behaviors and weaning weight of small-tailed han lambs

Suckling behavior is essential for the growth, health, and welfare of the lamb. The factors that influence the suckling-related behavior varied across breeds, and they remain unclear in Small-tailed Han lamb. This study aims to investigate the effects of ewe parity, lamb sex, and birth order on the suckling-related behaviors of Small-tailed Han lamb. The neonatal behaviors of 36 lambs were observed during the first week after birth using focal-animal sampling methods, and the levels of cholecystokinin (CCK), endogenous opioid peptides and growth hormone (GH) were measured with ELISA methods before weaning. Results showed that male lambs began standing and suckling behaviors earlier than female lambs, and the duration of each suckling bout was longer in male lambs (P < 0.05). Lambs born to multiparous ewes more frequently suckled and attempted to stand earlier than lambs from primiparous ewes (P < 0.05). The weaning weights of male lambs and lambs from multiparous ewes were heavier, and the serum levels of CCK, opioid peptides, and GH were sometimes higher in these lambs before weaning (P < 0.05). Meanwhile, lamb birth order has no significant effect on the suckling-related behaviors of lambs (P > 0.05). In addition, the suckling-related behaviors of male lamb and lambs born to multiparous ewes were found to strongly correlate with each other. In conclusion, lamb sex and ewe parity could affect the suckling-related behaviors and weaning weights of Small-tailed Han lambs. Moreover, male lambs and lambs born to multiparous ewes seemed to have better suckling-related behaviors. Many of these behaviors were highly connected with one another. These phenomena may be related to the higher serum levels of CCK, opioid peptides, and GH. The effects of lamb sex on suckling-related behaviors were different from those of other breeds in previous research. The male lambs were observed to initiate sucking-related behaviors earlier in this study. Our findings will also help in extensively understanding the variability in the effects of these factors on suckling-related behavior across sheep breeds.

Association between single-nucleotide polymorphism in PIK3CD gene and litter size in Small Tail Han sheep

The p110δ isoform of the PI3K catalytic subunit (encoded by the PIK3CD gene) is a key component of the PI3K pathway for follicle growth in mammalian ovarian granulosa cells. Nevertheless, little is known about the association of its polymorphisms with ovine litter size. In this study, the distribution of different genotypes of two SNPs in the PIK3CD gene was calculated in more than forty sheep breeds, and the associations between SNPs and litter size in Small Tail Han (STH) sheep were also analyzed. Besides, the mRNA expression of the PIK3CD gene was also detected in some reproduction-related tissues. The results showed that the “A” allele frequency was higher in rs412889931 (g.41926327G > A) in a typical polytocous sheep breed (p < 0.01). The association's analysis showed rs412889931 was correlated with ovine fecundity as assessed by three parity litter sizes (p < 0.05). Finally, we found the expression of PIK3CD in the ovary had significant differences in different fecundity sheep breeds, indicating that SNP may regulate the litter size by influencing the PIK3CD gene expression. The present results demonstrated that rs412889931 could be used in the marker-assisted selection of the litter size in sheep breeding.

Newly reported 90-bp deletion within the ovine BMPRIB gene: Does it widely distribute, link to the famous FecB (p.Q249R) mutation, and affect litter size?

The study of the BMPRIB gene polymorphisms has become of great importance in sheep, because it provides critical genetic tools to improve reproductive efficiency in ewes. The purposes of this study were: to assess the genetic diversity of the 90-bp deletion polymorphism within the BMPRIB gene in 52 various sheep breeds; to examine its linkage to the p.Q249R variant in the same gene, as well as to analyze its association with litter size. Herein, a total of 2313 various sheep individuals were used to detect the presence of the 90-bp deletion, among them the six breeds (Australian White (AUW), Small-Tail Han (STH), Guiqian semi-fine wool (GQSFW) sheep, etc.) were genotyped using PCR-based genotyping technology (n = 1636), and 47 breeds worldwide (including STH sheep) were genotyped via whole genome sequencing (WGS) method (n = 677). Genotyping outcomes revealed that the polymorphism was segregated in 45 of 52 breeds with varying frequencies (0.05–0.93). It is pertinent to note that the 90-bp deletion is not linked to the famous p.Q249R SNP in population of interest, except in high prolific Hu sheep. The association analysis indicated that the Del-90-bp variant showed no significant association (P > 0.05) with litter size in AUW (n = 625), GQSFW (n = 75) and STH (n = 38) ewes. Nevertheless, further investigation is needed on the importance of the Del-90-bp variant as a DNA marker that could possibly serve as an additional selection criterion in breeding ewes with high productivity.

Association analysis of GHR gene polymorphism with growth traits in sheep

In this study, polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was employed to investigate the polymorphism of GHR gene and the correlations of polymorphic sites with growth traits. The results showed that GHR detected CC, CD and DD genotypes in the five sheep populations. GHR gene had the highest DD genotype frequencies in Yuxi fatty-tailed sheep, Dorper sheep, Henan large-tailed han sheep, Hu sheep and small-tailed han sheep, being 0.889, 0.784, 0.785, 0.529 and 0.750, respectively. The correlation analysis indicated that GHR gene had significant correlations with chest circumference and abdomen circumference of sheep

Thyroid Transcriptomic Profiling Reveals the Follicular Phase Differential Regulation of lncRNA and mRNA Related to Prolificacy in Small Tail Han Sheep with Two FecB Genotypes.

Long non-coding RNA (lncRNA) accounts for a large proportion of RNA in animals. The thyroid gland has been established as an important gland involved in animal reproduction, however, little is known of its gene expression patterns and potential roles in the sheep. Herein, RNA-Seq was used to detect reproduction-related differentially expressed lncRNAs (DELs) and mRNAs (DEGs) in the follicular phase (FT) FecBBB (MM) and FecB++ (ww) genotypes of Small Tail Han (STH) sheep thyroids. Overall, 29 DELs and 448 DEGs in thyroid between MM and ww sheep were screened. Moreover, GO and KEGG enrichment analysis showed that targets of DELs and DEGs were annotated in biological transitions, such as cell cycle, oocyte meiosis and methylation, which in turn affect reproductive performance in sheep. In addition, we constructed co-expression and networks of lncRNAs-mRNAs. Specifically, XLOC_075176 targeted MYB, XLOC_014695 targeted VCAN, 106991527 targeted CASR, XLOC_075176 targeted KIFC1, XLOC_360232 targeted BRCA2. All these differential lncRNAs and mRNAs expression profiles in the thyroid provide a new resource for elucidating the regulatory mechanism underlying STH sheep prolificacy.

Effects of pelletized corn straw and alfalfa hay-based total mixed ration on growth performance, blood characteristics and rumen fermentation of small-tailed han sheep

Yang, Y., Wang, B., Li, H., Chen, B. Y. and Yu, Z. 2022. Effects of pelletized corn straw and alfalfa hay-based total mixed ration on growth performance, blood characteristics and rumen fermentation of small-tailed Han sheep. Animal Nutrition and Feed Technology, 22: 469–480.

Effects of FecB Mutation on Estrus, Ovulation, and Endocrine Characteristics in Small Tail Han Sheep.

The Booroola fecundity gene (FecB) has a mutation that was found to increase the ovulation rate and litter size in Booroola Merino sheep. This mutation is also associated with the fecundity of small-tail han (STH) sheep, an important maternal breed used to produce hybrid offspring for mutton production in China. Previous research showed that the FecB gene affects reproduction in STH sheep, based on litter size records. However, the effects of this gene on estrus, ovulation, and endocrine characteristics in these sheep remain unclear. Here, we analyzed the traits mentioned earlier and compared them among the three FecB genotypes of STH ewes using estrus synchronization. Overall, 53 pluriparous ewes were selected from among 890 STH ewes and subjected to FecB genotyping for experiments to characterize estrous and ovulation rates. FecB heterozygous (+B) ewes presented an earlier onset of estrus (42.9 ± 2.2 h) and a shorter estrous cycle (17.2 ± 0.2 days) (P ≤ 0.05). The ovulation rates increased with the increasing copy number of the B allele (P ≤ 0.01). Ovulation time showed no significant differences among the three FecB genotypes. The serum concentrations of follicle-stimulating hormone (FSH), luteinizing hormone, estrogen (E2), and progesterone (P4) were measured in 19 of the ewes. Serum concentrations of E2 and FSH dramatically varied around the time of behavioral estrus. In FecB mutant homozygous (BB) ewes, E2 concentration had two peaks, which were higher (P ≤ 0.05) than those of ++ genotypes. FSH concentration of BB ewes was higher (P ≤ 0.05) than that of the ++ ewes just after estrus. The expression of the estrogen receptor 1 (ESR1) gene in the +B genotype was higher than in the other genotypes. Based on the data for the reproductive performance of STH ewes with the three FecB genotypes, our study suggests that the development of follicles in ewes with the B allele is dependent on the response to FSH regulated by E2 in the early stage. +B ewes, exhibiting moderate ovulation and litter size and a shorter estrous cycle, can be highly recommended in sheep crossbreeding systems for commercial mutton production. Moreover, this study provides useful information to conserve better and use the genetic resources of STH sheep in China.

Comparative whey proteome analysis of small-tailed Han and DairyMeade ovine milk.

We characterized the proteome profile of mid-lactation small-tailed Han (STH) and DairyMeade (DM) ovine milk in order to explore physiological variation and differences in milk traits between the two breeds. Methodology combined a tandem mass tag (TMT) proteomic approach with LC-MS/MS technology. A total of 656 proteins were identified in STH and DM ovine milk, of which 17and 29 proteins were significantly upregulated (P < 0.05) in STH and DM, respectively. Immune-related proteins and disease-related proteins were highly expressed in STH milk, whereas S100A2 and AEBP1 were highly expressed in DM milk, which had beneficial effects on mammary gland development and milk yield. Our results provide a theoretical basis for future breeding of dairy sheep.