Decoding molecular features of bovine oocyte fate during antral follicle growth via single-cell multi-omics analysis.

Antral follicle size is a useful predictive marker of the competency of enclosed oocytes for yielding an embryo following in vitro maturation and fertilization. However, the molecular mechanisms underpinning oocyte developmental potential during bovine antral follicle growth are still unclear. Here, we used a modified single-cell multi-omics approach to analyze the transcriptome, DNA methylome and chromatin accessibility in parallel for oocytes and cumulus cells collected from bovine antral follicles of different sizes. Transcriptome profiling identified three types of oocytes (Small, Medium and Large) that underwent different developmental trajectories, with Large oocytes exhibiting the largest average follicle size and characteristics resembling metaphase-II oocytes. Differential expression analysis and real-time PCR assay showed that most replication-dependent histone genes were highly expressed in Large oocytes. The joint analysis of multi-omics data revealed that the transcription of 20 differentially expressed genes in Large oocytes was associated with both DNA methylation and chromatin accessibility. In addition, oocyte-cumulus interaction analysis showed that inflammation, DNA damage, and p53 signaling pathways were active in Small oocytes, which had the smallest average follicle sizes. We further confirmed that p53 pathway inhibition in in vitro maturation experiments using oocytes obtained from small antral follicles could improve the quality of oocytes and increased the blastocyte rate after in vitro fertilization and culture. Our work provides new insights into the intricate orchestration of bovine oocyte fate determination during antral folliculogenesis, which is instrumental for optimizing in vitro maturation techniques to optimize oocyte quality.

Gene co-expression network and differential expression analyses reveal key genes for weaning weight in Simmental-Holstein crossbred cattle.

Weaning weight is a key indicator of the early growth performance of cattle. An understanding of the genetic mechanisms underlying weaning weight will help increase the accuracy of selection of breeding animals. In order to identify candidate genes associated with weaning weight in Simmental-Holstein crossbred cattle, this study generated RNA-Sequencing (RNA-seq) data from 86 crossbred calves (37 males and 49 famales) and measured their weaning weight and body size traits (wither height, body length, chest girth, rump width, and rump length). Differential gene expression analysis and weighted gene co-expression network analysis (WGCNA) were performed. A total of 498 differentially expressed genes (DEGs) were identified between the low weaning weight (LWW) group and the high weaning weight (HWW) group. Weaning weight was transcriptionally correlated (FDR < 0.05) with four of the eleven co-expression gene modules. By intersecting DEGs and hub genes of the four modules, we identified a final set of 37 candidate genes enriched in growth, development, or immune-related processes. In addition, one co-expression module was significantly correlated with all the five body size traits (P < 0.05), from which MX1 was identified as a key candidate gene through protein-protein interaction (PPI) analysis of hub genes. Further evidence from cattle transcriptome-wide association study analysis (TWAS) and human phenome-wide association study (PheWAS) validated significant associations of CACNA1S, SEMA7A, VCAN, CD101, CD19, and CSF2RB with growth and development traits (P < 0.05). Notably, CACNA1S and CD19 were also associated with typical immune traits such as B cell proliferation, differentiation, and activation. In conclusion, this study reveals new candidate genes significantly associated with weaning weight in Simmental-Holstein crossbred cattle, providing a basis for further exploration of the genetic mechanisms behind growth traits of cattle.

Whole-genome resequencing of the native sheep provides insights into the microevolution and identifies genes associated with reproduction traits.

BACKGROUND: Sheep genomes undergo numerous genes losses, gains and mutation that generates genome variability among breeds of the same species after long time natural and artificial selection. However, the microevolution of native sheep in northwest China remains elusive. Our aim was to compare the genomes and relevant reproductive traits of four sheep breeds from different climatic environments, to unveil the selection challenges that this species cope with, and the microevolutionary differences in sheep genomes. Here, we resequenced the genomes of 4 representative sheep breeds in northwest China, including Kazakh sheep and Duolang sheep of native breeds, and Hu sheep and Suffolk sheep of exotic breeds with different reproductive characteristics. RESULTS: We found that these four breeds had a similar expansion experience from ~ 10,000 to 1,000,000 years ago. In the past 10,000 years, the selection intensity of the four breeds was inconsistent, resulting in differences in reproductive traits. We explored the sheep variome and selection signatures by FST and θπ. The genomic regions containing genes associated with different reproductive traits that may be potential targets for breeding and selection were detected. Furthermore, non-synonymous mutations in a set of plausible candidate genes and significant differences in their allele frequency distributions across breeds with different reproductive characteristics were found. We identified PAK1, CYP19A1 and PER1 as a likely causal gene for seasonal reproduction in native sheep through qPCR, Western blot and ELISA analyses. Also, the haplotype frequencies of 3 tested gene regions related to reproduction were significantly different among four sheep breeds. CONCLUSIONS: Our results provide insights into the microevolution of native sheep and valuable genomic information for identifying genes associated with important reproductive traits in sheep.

Polymorphisms and association of GRM1, GNAQ and HCRTR1 genes with seasonal reproduction and litter size in three sheep breeds.

Litter size is one of the important economic traits of livestock. Seasonal oestrus, ovulation and lambing of sheep have severely restricted the development of sheep farming in Xinjiang, China. The purpose of this study was to investigate the polymorphisms and genetic correlation between GRM1, GNAQ and HCRTR1 genes and the seasonal reproduction and litter size in three sheep breeds. The DNA mixed pool sequencing and PCR-SSCP methods were used to detect single nucleotide polymorphisms (SNPs) of GRM1, GNAQ and HCRTR1 genes in seasonal oestrous (Kazakh and Chinese Merino [Xinjiang Junken type]) and perennial oestrous (Hu) sheep breeds. The association between genetic polymorphism and litter size was also analysed. The results showed that T945C in exon 2 of GRM1 gene, C589T in exon 2 of HCRTR1 gene and A191G in exon 2 of GNAQ gene were identified by Sanger sequencing, and three genotypes were existed in each SNP site, which all belonged to the synonymous mutation. GRM1 (CC), GNAQ (GA) and HCRTR1 (TC) were the dominant genotypes of seasonal reproduction and litter size in Kazakh sheep and Chinese Merino sheep, respectively, while, in perennial oestrous Hu sheep populations, the dominant genotypes were GRM1 (TC), GNAQ (GA) and HCRTR1 (TC), respectively, and association analysis also confirmed the results. The above results implied that GRM1, GNAQ and HCRTR1 genes are significantly associated with lambing traits in Kazakh, Chinese Merino and Hu sheep. Among them, the locus of GRM1 (T945C), GNAQ (A191G) and HCRTR1 (C589T) might be considered as a potential molecular marker, which controls seasonal reproduction and litter size in sheep.

Comparative Analysis and Identification of Differentially Expressed microRNAs in the Hypothalamus of Kazakh Sheep Exposed to Different Photoperiod Conditions.

MicroRNAs (miRNA) plays an important role in several mammalian biological regulatory processes by post-transcriptionally regulating gene expression. However, there is little information on the miRNAs involved in the photoperiodism pathway that controls seasonal activity. To enhance our knowledge on the effect of different photoperiod conditions on miRNA, we divided Kazakh sheep into two groups: one exposed to a long photoperiod (LP, 16L:8D) and another with exposed to a short photoperiod (SP, 8L:16D) under supplemental feeding conditions. Further we compared the related miRNAs and target genes between the two groups. Fifteen differentially expressed miRNAs were identified, which were associated with 310 regulatory pathways covering photoperiodism, reproductive hormones, and nutrition. The miR-136-GNAQ pair was selected and validated as a differentially expressed, and a dual-luciferase reporter assay showed that the negative feedback loop existed between them. Examination of the expression profile revealed that the GNAQ expression was low in the estrous females both under LP and SP conditions, but high expression of GNAQ was observed in the anestrous females under LP conditions. Moreover, functional analysis revealed that KISS1 and GnRH expression was upregulated when GNAQ expression was downregulated in the hypothalamic cells, whereas DIO2 and TSHB expression was downregulated. Thus, miR-136-GNAQ might act as a switch in the regulation of seasonal estrus under different photoperiod conditions. These findings further enrich our understanding of the relationship between miRNAs and seasonal regulation of reproductive activity. Furthermore, our study provides novel insights into the miRNA-mediated regulatory mechanisms for overcoming photoinhibition in the seasonally breeding mammals, such as Kazakh sheep.

The effect of GNAQ methylation on GnRH secretion in sheep hypothalamic neurons.

Kazakh sheep are seasonal estrous animals, and gonadotropin-releasing hormone (GnRH) is the key to fertility regulation. The nutritional level has a certain regulatory effect on estrous, and vitamin B folate plays a role in DNA methylation, directly participating in the process. The goal of this study was to determine whether folate is involved in GnAQ methylation and its effect on GnRH secretion. The hypothalamic neurons of Kazakh fetal sheep were treated with folate at concentrations of 0 mg/mL, 4 mg/mL, 40 mg/mL, and 80 mg/mL. GnAQ promoter methylation, DNMT1, GnAQ expression, and GnRH secretion following treatment with different concentrations of folate were analyzed. One CpG site was methylated in the GNAQ promoter with 40 mg/mL folic acid, and no CpG methylation was found in the other groups. GnAQ expression was related to folate concentration and showed a trend of increasing first and then decreasing. The GnRH expression level in the 40 mg/mL folate group was significantly higher than in the other three groups ( P < .05). These results demonstrate that the appropriate folate concentration promoted GANQ promoter methylation, which in turn affected GnRH secretion.

Identification and analysis of microRNAs-mRNAs pairs associated with nutritional status in seasonal sheep.

Given the important role of nutritional status for reproductive performance, we aimed to explore the potential microRNA (miRNA)-mRNA pairs and their regulatory roles associated with nutritional status in seasonal reproducing sheep. Individual ewes were treated with and without 0.3 kg/day concentrates, and the body condition score, estrus rate, and related miRNAs and target genes were compared. A total of 261 differentially expressed miRNAs were identified, including 148 hypothalamus-expressed miRNAs and 113 ovary-expressed miRNAs, and 349 target genes were predicted to be associated with nutritional status and seasonal reproduction in sheep. Ultimately, the miR-200b-GNAQ pair was screened and validated as differentially expressed, and a dual luciferase reporter assay showed that miR-200b could bind to the 3'-untranslated region of GNAQ to mediate the hypothalamic-pituitary-ovarian axis. Thus, miR-200b and its target gene GNAQ likely represent an important negative feedback loop, providing a link between nutritional status and seasonal reproduction in sheep toward enhancing reproductive performance and productivity.

Nutritional status affects the microRNA profile of the hypothalamus of female sheep.

Recent studies on the seasonal regulation of the oestrous cycle in sheep have focussed mainly on the responses to photoperiod. However, the brain systems that control reproductive activity also respond to nutritional inputs, although the molecular mechanisms involved are not completely understood. One possibility is that small, non-coding RNAs, such as micro-RNAs (miRNAs), have significant influence. In the present study, the amounts and characteristics of miRNAs in hypothalamus from oestrous and anestrous ewes, fed low- or high-nutrient diets, were compared using Illumina HiSeq sequencing technology. In total, 398 miRNAs, including 261 novel miRNAs, were identified in ewes with an enhanced nutritional status (HEN), whereas 384 miRNAs, including 247 novel miRNAs, were identified in the ewes with a lesser nutritional status (HAN). There were eight conserved and 140 novel miRNAs expressed differentially between the two libraries. Based on quantitative real-time polymerase chain reaction, six miRNAs were assessed to verify the accuracy of the library database. Moreover, the correlation between the miRNA target and several upstream and downstream genes in the oestrus-related pathways were also verified in hypothalamus nerve cells. According to the results, nutritional status plays an important role in oestrous regulation in sheep, and the hypothalamic processes and pathways induced by nutritional signals (folic acid and tyrosine) are different from those induced by photoperiodic regulation of oestrus. We have expanded the repertoire of sheep miRNAs that could contribute to the molecular mechanisms that regulate the initiation of oestrous cycles in anestrous ewes in response to the influence of nutritional status.

Multi-omics analysis reveals flavor differences in Xinjiang brown beef with varying intramuscular fat contents.

Beef flavor plays a crucial role in consumer preference, yet research on this trait has been limited by past technological constraints. Intramuscular fat (IMF) is a key determinant of beef quality, influencing taste, marbling, and overall flavor. Xinjiang brown cattle (XBC), an indigenous breed from northern Xinjiang, China, presents significant variation in meat quality, with IMF content ranging from 0.2 % to 4.3 % within the population. This variation suggests strong potential for breeding improvement. In this study, we selected 82 XBC for slaughter and meat quality analysis, categorizing them based on IMF content. Using two-dimensional gas chromatography-time-of-flight mass spectrometry (GC×GC-TOF MS), we analyzed volatile flavor compounds across different beef cuts (Longissimus dorsi, Semitendinosus, Supraspinatus). Our results showed that beef with higher IMF levels exhibited enhanced flavor profiles, characterized by sweet, green, fruity, and waxy notes, while castrated bulls displayed the weakest flavor intensity. Metabolomic analysis further revealed significant differences in flavor substances between high and low IMF content beef. RNA-Seq analysis identified key genes (AQP4, FZD2, FADS1, BPG1, CEBPD, FABP4) associated with flavor formation, offering valuable insights for breeding strategies aimed at improving XBC meat quality. This comprehensive study provides a robust theoretical foundation for advancing the genetic improvement of XBC.

Comparative Analysis of Nkx2-5/GATA4/TBX5 Expression in Chicken, Quail and Chicken-quail Hybrids during the Early Stage of Cardiac Development in Embryos.

The present study makes an investigation into expression of genes related to cardiac development in chicken, quail and chicken-quail hybrids during the early stage of embryogenesis. Real-time PCR was used to detect mRNA expressions of Nkx2-5, GATA4 and TBX5 in the heart of chicken, quail and chicken-quail hybrids embryos during the 3rd to 7th days of incubation. Results showed that NKX2-5 mRNA displayed a similar expression trend in chicken, quail and chicken-quail hybrids. The initial and highest expression of Nkx2-5 was focused on the 3rd day of incubation, then it declined till 5th day of incubation, thereafter, it fluctuated. Expression of Nkx2-5 gene in quail was significantly higher than in chicken and chicken-quail hybrids, and no significant difference was observed between the two latter species. GATA4 mRNA showed a similar expression trend between chicken and quail, which displayed a steady increase from 3rd to 6th d, then, the expression level decreased. However, GATA4 mRNA expression in chicken-quail hybrids was significantly higher than that in chicken and quail from 3rd to 5th d (p<0.01), but significantly lower than that in chicken and quail during the later stage of the experiment (p<0.05), due to the dramatic drop from 5th d onwards (p<0.01). TBX5 mRNA expression in chicken and quail showed the same trend as GATA4 expressed in the two species. Furthermore, TBX5 expression in chicken-quail hybrids was significantly higher than that in chicken and quail during the whole course of experiment, although relatively lower TBX5 expression was detected in the early stage. In conclusion, Nkx2-5, GATA4 and TBX5 genes showed dynamic changes during the process of cardiac development in chicken, quail and their hybrids embryos. In addition, the expression trend in chicken was similar to that in quail, and there was no significant difference for gene expression level, except NKX2-5. However, expression of these genes in chicken-quail hybrids was significantly different from their parents, the difference mechanism needs to be further explored.

Differential expressions of MHC-DQB1 mRNA in Chinese merino sheep infected with Echinococosus granuclosus.

The purpose of the present study was to investigate the dynamic changes of MHC-DQB1 mRNA expression in sheep infected with Echinococosus granuclosus. A total of 14 healthy Chinese merino sheep were experimentally infected with E. granuclosus. The blood samples were collected on days 0 (initiation of the infection), 7, 21, 30, and 60 post-infection, respectively. On day 60 post-infection, when the experiment was terminated, all sheep were euthanized to make a diagnosis of cystic echinococcosis (CE) using routine meat inspection and microscopical examination, respectively. The sheep were then divided into two groups according to the diagnostic results: group A (n = 8) consisted of sheep which were diagnosed as CE infection, while group B (n = 6) comprised sheep diagnosed as self-cured or healthy controls. Blood samples obtained during the period of the study were correspondingly divided into groups A and B. The mRNA expression levels of DQB1 revealed significant alterations detected at different stages of E. granuclosus infection in the two groups. Results showed that in group A, DQB1 mRNA expression underwent a progressive increase from day 0 to day 21 post-infection (P = 0.073), and suddenly, suffered from a dramatic drop until day 30 post-infection, and then jumped rapidly and peaked on day 60 post-infection (P = 0.004). Meanwhile, in group B, DQB1 mRNA expression displayed a sharp increase from day 0 to day 7 post-infection (P = 0.000), which thereafter showed a marked decrease until day 30 post-infection, and experienced a plateau from day 30 to day 60 post-infection, remaining at or above that on day 0. It is concluded that DQB1 mRNA expression levels varied in different stages of E. granuclosus infection in sheep. In addition, it appears that the ability to eliminate the parasites possibly depends, at least in part, on the DQB1 expression in the early stage of infection, especially in the first week post-infection.

[Expression levels of Slc7a11 in the skin of Kazakh sheep with different coat colors].

Slc7a11 belongs to solute transporter gene family, encoding cystine/glutamate transporter xCT. It regulates switching between eumelanin and pheomelanin synthesis. In the present study, Real-time PCR was used to detect the mRNA expression levels of Slc7a11 in the skin of Kazakh lambs with different coat colors (black, brown and white), and then the prokaryotic expression plasmid PET-32a-sxCT was constructed to induce the expression of fusion protein. The target pro-tein was purified by Ni-NTA affinity chromatographic separation, and then was used to immunize rabbit in order to produce rabbit anti-sxCT polyclonal antibody. Finally, the expression levels of sxCT were detected in the skin of Kazakh lambs with different hair colors by Western blotting analysis. Results showed that the mRNA expression levels of Slc7a11 differed significantly in the skin of Kazakh lambs with different coat colors, with the highest level in brown coat color, followed by the black, and then the white. The sxCT protein was also detected in the skin of different coat colors by polyclonal antibody, with the highest level in brown coat color, followed by the black, and then the white. It is, therefore, concluded that slc7a11 gene might be associated with the phenotype of coat color in Kazakh sheep.

Changeable effects of coexisting heavy metals on transfer of cadmium from soils to wheat grains.

Cadmium (Cd) and other heavy metals usually coexist in soils. Effects of coexisting heavy metals on the accumulation and transfer of Cd in field soils by wheat remain poorly understood. Here we revealed changeable effects of coexisting Pb, Zn and Cu on the Cd transfer from soils to wheat grains. Soil burdens of Cd were found to exhibit positive correlations (r = 0.459-0.946) with those of coexisting Pb, Zn and Cu (particularly Pb). Effects of three coexisting metals on to the uptake of Cd by wheat varied in the directions and/or extents with types of metals and transfer processes of Cd. Coexisting Zn inhibited the uptake of Cd by wheat grains to higher extent than Pb and Cu. Soil Zn, along with soil Cd, soil pH and soil Ca, was used to construct the predictive model of grain Cd (R2 = 0.868). External verifications of the model on 572 datasets of large representation performed well. The predictive accuracy was about 54%, 73% and 89% for a factor of 1, 2 and 5 above and below the ideal fit, respectively. This finding has practical interest in risk assessments and remediation measures of Cd-contaminated soil sites in regional scales.

Insights into site-specific influences of emission sources on accumulation of heavy metal(loid)s in soils by wheat grains.

Excessive accumulation of heavy metal(loid)s in agricultural environment usually originates from anthropogenic activities. Both large diversities of emission sources and complexity of plant accumulation challenge the understanding of the site-specific effects of emission sources on heavy metal(loid)s in wheat grains. Herein, both soil samples and wheat grain samples (n = 80) were collected from the farmland of Jiyuan City, China. Soil and grain burdens of heavy metal(loid)s were determined by inductively coupled plasma mass spectrometry (ICP-MS) and/or X-ray fluorescence spectrometry (XRF). The quotients (Q) were developed to indicate relative impacts of industrial plants and traffic to soil sites. Principal component analysis-absolute principal component scores-multivariate linear regression (PCA-APCS-MLR) analysis was conducted to reveal the source contributions to heavy metal(loid)s in grains, considering Q values, soil, and wheat grain data. Results showed that contributions of main sources and factors drastically varied with soil sites, and usually overlapped to different extents. For grain Cd and grain Pb, natural soil silicate (0.066/0.104 mg/kg) and iron-bearing minerals (- 0.044/ - 0.174 mg/kg) contributed to high extents, while metal smelting activities (0.018/0.019 mg/kg) and agronomic activities (- 0.017/ - 0.019 mg/kg) unexpectedly posed low or moderate contributions. The pH-mediated availability of soil Cd (0.035 mg/kg) and the sand-dust weather (0.028 mg/kg) also made considerable contributions to grain Cd. For grain As, both natural soil iron-bearing (- 0.048 mg/kg) and silicate minerals (- 0.013 mg/kg) made negative contributions. The results benefit to the decision-making of pollution remediation of farmland soils in the regional scales.

[Characteristics, Sources, and SOAP of VOCs During Winter in Jiyuan].

Haze pollution events often occur in the heavy industry city of Jiyuan. Volatile organic compounds (VOCs) are the precursors of secondary organic aerosol (SOA), which accounts for 15%-20% of particulate matter (PM2.5). Here, PM2.5, O3, VOCs, and trace gases were monitored by using online instruments in Jiyuan from December 1st to 31st. The characteristics, sources, and secondary organic aerosol potential (SOAP) of VOCs were analyzed. The mean concentrations of TVOC were (54.3±27.5)×10-9. Alkanes, halocarbons, and alkynes were the predominant VOCs. The positive matrix factorization model was used to identify and apportion VOCs sources. Eight major sources of VOCs were identified, which included liquefied petroleum gas (LPG) or natural gas (NG), the polyvinyl chloride (PVC) industry, vehicular exhaust, the coking industry, solvent usage, industry, technological process, and fuel evaporation. The SOAP of aromatics was the largest. Among them, BTEXs were the dominant contributors to SOAP.

Targeting GNAQ in hypothalamic nerve cells to regulate seasonal estrus in sheep.

Kazakh sheep are typical seasonal estrus animals. Their reproductive system regulation mainly involves the complex regulation of the hypothalamic-pituitary-gonadal axis (HPGA), which is also closely related to reproductive hormone secretion. Gonadotropin-releasing hormone (GnRH), synthesized and secreted by the hypothalamus, is the key to controlling sheep reproductive activity. We studied how GNAQ (G protein subunit alpha q) regulates estrus in sheep by controlling GnRH expression and secretion. We used hypothalamic nerve cells as the research model. GNAQ overexpression and RNA interference vectors were constructed and transfected into the hypothalamic nerve cells of fetal Kazakh sheep. qPCR, western blotting, and enzyme-linked immunosorbent assay were used to detect GNAQ gene expression in Kazakh ewe tissues and analyze its regulatory effect on GnRH expression in the hypothalamic nerve cells. The fetal sheep hypothalamic nerve cells were successfully isolated and cultured. qPCR and cell immunofluorescence showed that the purity of positive cells was >95%. The tissue expression profile showed that there were different degrees of GNAQ gene expression in the Kazakh ewe tissue. Expression levels were relatively higher in the hypothalamus, pituitary, brain, and uterine tissues. When GNAQ expression was downregulated in the hypothalamic nerve cells, the upstream genes KISS1 (kisspeptin), GPR54 (KISS1 receptor), and ER (estrogen receptor) were all upregulated, as were the downstream genes PLCB1 (phospholipase C beta 1), PRKCB (protein kinase C beta), and GNRH. At the same time, GnRH secretion levels were also upregulated. GNAQ regulated its downstream gene PLCB1 in the hypothalamic nerve cells, and directly regulated GnRH expression and secretion through the calcium and PRKC signaling pathways. GNAQ also regulated kisspeptin expression, subsequently regulating GnRH expression and secretion indirectly through the kisspeptin-GPR54 signaling pathway. Our results are of great importance for improving the reproductive performance of seasonal-estrus sheep.

Identification of SNPs within the sheep PROP1 gene and their effects on wool traits.

Regarding mutations of PROP1 (Prophet of POU1F1) gene significantly associating with combined pituitary hormone deficiency (CPHD) in human patients and animals, PROP1 gene is a novel important candidate gene for detecting genetic variation and growth, reproduction, metabolism traits selection and breeding. The aim of this study was to detect PROP1 gene mutation of the exon 1-3 and its association with wool traits in 345 Chinese Merino sheep. In this study, on the basis of PCR-SSCP and DNA sequencing methods, ten novel SNPs within the sheep PROP1 gene, namely, AY533708: g.45A>G resulting in Glu15Glu, g.1198A>G, g.1341G>C resulting in Arg63Ser, g.1389G>A resulting in Ala79Ala, g.1402C>T resulting in Leu84Leu, g.1424A>G resulting in Asn91Ser, g.1522C>T, g.1556A>T, g.1574T>C, g.2430C>G were reported. In addition, association analysis showed that three genotypes of P4 fragment were significantly associated with fiber diameter in the analyzed population (P=0.044). These results strongly suggested that polymorphisms of the PROP1 gene could be a useful molecular marker for sheep breeding and genetics through marker-assisted selection (MAS).

Antibody and cytokine responses to hydatid in experimentally infected Kazakh sheep with hydatidosis resistance haplotype.

Different MHC haplotype of Kazakh sheep has different resistance and susceptibility of hydatidosis. Notably, the MvaIbc-SacIIab-Hin1Iab haplotype of MHC-DRB1 exon two was associated with resistance hydatidosis. In order to analyze the antibody and cytokine responses to hydatidosis in Kazakh sheep with hydatidosis resistance haplotype, eight Kazakh sheep with the haplotype of MvaIbc-SacIIab-Hin1Iab were chosen as the test group, and other eight, which were not associated with hydatidosis resistance or susceptibility, were taken as control. After experimentally infected with hydatid orally, the blood was collected on 0, 7, 14, 30, 45, 60, 75, 90, 105, and 120 days. Serum and mRNA level of the cytokines IL-2, IFN-γ, TNF-α, IL-4, and IL-10 were evaluated by ELISA and fluorescence quantitative real-time polymerase chain reaction, respectively. The total white blood cells and leukomonocytes were determined by automation cytoanalyze. The level of IgE, IgG, and IgM were evaluated by ELISA. The results showed that the total white blood cells and leukomonocytes in test group were significantly higher than in control on 7, 45, 90, and 105 days post-infection (p.i.). The serum level of IL-2 in test group was significantly higher than in control on 45 days p.i., while the difference of IL-2 mRNA expression between test and control group was not significant. The serum level of TNF-α in test group was significantly higher than in control at 90 and 105 days p.i., and the TNF-α mRNA in test group was also significantly higher than in control on 90 days p.i. The level of IgE, IgG, and IgM in test group was higher than in control, but none was significant. The results suggested that the test group, which was predominant of Th1, could induce the protective immunity, while the control, which was predominant of Th2, could induce the susceptibility to infection of hydatidosis.

[The gene ontology and electro localization of ovine skin derived EST-SSR markers].

Abstract: In order to study the potential gene function of ovine EST-SSR markers, nine original EST of Ovine Skin Derived polymorphic EST-SSR loci, which were developed in an early study by our lab, were ontology annotated and Electro localized. The results revealed that the original ESTs of the six loci had high homology with known genes and three of them probably played an important role in wool traits. Compared with its cDNA library, 8 loci were located on chromosomes of cattle. The homology of chromosomes between cattle and sheep was estimated based on the similarity coefficients calculated by positioning markers. Additionally, NJ clustering tree was establishedto serve for electro localization of ovine EST-SSR markers. Finally, 8 EST-SSR markers were successfully positioned on ovine chromosomes. The results from this study not only provide references for further studies on genetic mapping, in silico cloning of key genes for wool traits, but also are helpful to the researchs of chromosome evolution in animal.

Thiol-functionalized nano-silica for in-situ remediation of Pb, Cd, Cu contaminated soils and improving soil environment.

Heavy metal contamination has been threatening the health of human beings. To decrease the bio-toxicity of heavy metals, a thiol-functionalized nano-silica (SiO2-SH) was adopted to remediate the soil contaminated by lead (Pb), cadmium (Cd) and copper (Cu). The remediation effect of SiO2-SH on contaminated soils was investigated by the uptake of the heavy metals into lettuce and pakchoi in pot experiment. The bio-toxicity of the SiO2-SH was evaluated, and its immobilization mechanisms were proposed by the fraction distribution of Cd, Pb and Cu. It was found that the SiO2-SH can significantly reduce the uptake of Cd, Pb, Cu into pakchoi by 92.02%, 68.03%, 76.34% and into lettuce by 89.81%, 43.41%, 5.76%, respectively. The chemical species analyses of Cd, Pb, Cu indicate SiO2-SH can transform the heavy metal in acid soluble states into reducible fraction and oxidizable fraction, thereby inhibiting the extraction of heavy metals into soil solution. The concentrations of microbial biomass carbon, organic matter, and cation exchange capacity of the soil increased while the soil bulk density decreased after remediation. Those changes demonstrate that SiO2-SH not only has no bio-toxic impact on the soil environment but also improves the soil environment, which proves the prepared SiO2-SH is environmental-friendly. The SiO2-SH could be a promising amendment for heavy metal contaminated soils.