Genetics and non-genetics parameters of body weight for post-weaning traits in Raini Cashmere goats

Review on current status of Bonga, Afar, Menz, and Horro sheep breeds genetic improvement: Breeding program and progress

This working paper reviews the research and development in genetic improvement and breeding strategies of Bonga, Menz, Afar and Horro sheep in Ethiopia. This review aims to provide structured information regarding the Ethiopian indigenous sheep breeds (Bonga, Afar, Menz, and Horro) breeding programs and its progress. Genetic diversity is an essential element for genetic improvement, preserving populations, evaluation and adapting to variable environmental situations. Sustainable breeding techniques and sensible use of indigenous breed have been developed as result of recent research approaches to the conservation of sheep genetic resources. However, there is still growing interest of the government and of farmers in different breeding program to improve indigenous sheep breeds. There is no comprehensive study showing the performance of indigenous sheep breeds (Bonga, Afar, Menz, and Horro) genetic improvement under different breeding program and its progress, both biological and economic, to substantiate the argument on the benefit of different breeding programs for smallholders farmers. Programs for the sheep breeds Menz, Afar, Horro, and Bonga have now been developed at the community level. The idea behind the nucleus breeding program is to develop elite breeding animals by gathering the finest male and female breeding participants from the population in one central location. The first stage in creating a breeding program is defining the breeding goals. Planning breeding programs requires a thorough grasp of the farmers' (beneficiaries') breeding goals and production objectives. Therefore, this review makes it evident that numerous instruments and techniques, including choice experiments, participatory rural assessment procedures, and rating animals from flocks, have been used to define and ascertain the breeding aim of Afar, Horro, Bonga and Menz sheep breeds in Ethiopia.

Exploring candidate genes for heat tolerance in ovine through liver gene expression

Thermotolerance has become an essential factor in the prevention of the adverse effects of heat stress, but it varies among animals. Identifying genes related to heat adaptability traits is important for improving thermotolerance and for selecting more productive animals in hot environments. The primary objective of this research was to find candidate genes in the liver that play a crucial role in the heat stress response of Santa Ines sheep, which exhibit varying levels of heat tolerance. To achieve this goal, 80 sheep were selected based on their thermotolerance and placed in a climate chamber for 10 days, during which the average temperature was maintained at 36 °C from 10 a.m. to 4 p.m. and 28 °C from 4 p.m. to 10 a.m. A subset of 14 extreme animals, with seven thermotolerant and seven non-thermotolerant animals based on heat loss (rectal temperature), were selected for liver sampling. RNA sequencing and differential gene expression analysis were performed. Thermotolerant sheep showed higher expression of genes GPx3, RGS6, GPAT3, VLDLR, LOC101108817, and EVC. These genes were mainly related to the Hedgehog signaling pathway, glutathione metabolism, glycerolipid metabolism, and thyroid hormone synthesis. These enhanced pathways in thermotolerant animals could potentially mitigate the negative effects of heat stress, conferring greater heat resistance.

Association analysis for SNPs of BAAT and COL1A1 genes with cashmere production performance and other production traits in Liaoning cashmere goats

This study aimed to investigate the relationship between the polymorphism of bile acid-CoA: amino acid N-acyltransferase (BAAT) and collagen type I alpha 1 chain (COL1A1) genes and the production performance of Liaoning Cashmere goat (LCG). The potential single nucleotide polymorphisms (SNPs) of LCG were detected by sequence comparison of BAAT and COL1A1 genes and PCR-Seq polymorphism, and the effect of SNPs on production performance was analyzed by SPSS software. The results showed that three SNPs loci were detected in BAAT gene: G7900A, T7967C, C7998T, and one SNP locus T6716C was detected in COL1AL gene. At G7900A locus, the dominant genotype for cashmere performance was GG, and the dominant genotype for body measurement traits and milk production traits was AG. At T7967C locus, the dominant genotype for cashmere performance was TT, and the dominant genotype for body measurement traits and milk production traits was CC. At C7998T locus, TT was the dominant genotype for cashmere performance, body measurement traits, and milk production traits. At the T6716C locus, TT was the dominant genotype for cashmere performance, body measurement traits, and milk production traits. H1H1: AACC is the dominant haplotype combination. Therefore, this study will provide a reliable reference for future research on cashmere production performance, body measurement traits, and milk production traits of LCG.

Three novel simple sequence repeats (SSRs) identified by MALDI-TOF-MS method were associated with backfat in pig

Backfat trait is an important economic trait and highly heritable, but difficult to evaluate. Thus, it is of great significance to explore optimal backfat thickness of pigs by using marker-assisted selection (MAS) to speed up its breeding process and improve economic efficiency. This study aimed to investigate the relationship between genetic variations (e.g., SSRs) and backfat of Qinghai Bamei pigs using MALDI-TOF Mass Spectrometry (MALDI-TOF-MS). Herein, five alternative SSR loci (namely V1, V2, V3, V4 and V5) were selected for subsequent detection. The results suggested that 3 (141-, 143- and 145-), 3 (128-, 130- and 132-), 2 (160- and 162-), 2 (136- and 139-) and 3 (170-, 184- and 192-) alleles of V1, V2, V3, V4 and V5 were found, respectively. Subsequent analysis showed that there was linkage equilibrium among five SSRs and Hap19 (13.1%) (141-/132-/160-/139-/192-) had the highest haplotype frequency. Among these five SSR loci, V1, V2 and V3 loci were significantly associated to the backfat of Qinghai Bamei sows. These findings enriched the study of SSRs in Qinghai Bamei pigs, and (AC)n (Chr15:85485851-85485995), (AC)n (Chr10:52724583-52724713) and (TG)n (Chr4:90732644-90732802) could be utilized as the candidate locus for MAS in pig industry.HIGHLIGHTSFive novel SSR loci was identified in pigs through MALDI-TOF MS.V1, V2 and V3 loci was were significantly associated to the backfat of pigs.

Association analysis for SNPs of MSTN and IGFBP-3 genes with body size and other production traits in Liaoning Cashmere Goats

Liaoning cashmere goat (LCG) have tall bones, high cashmere production and outstanding meat production performance. In recent years, good breeding progress has not been made in terms of body size, meat yield, milk yield and other properties in terms of production. The study focused on the correlation between the SNPs of MSTN and IGFBP-3 genes with the body size performance, cashmere production and milk performance. The MSTN and IGFBP-3 gene sequence alignment and PCR-Seq polymorphism were used to detect the potential SNPs, and the correlation with production performance was analyzed by SPSS and SHEsis software. The results showed that the TT genotype at the T1662G locus of the MSTN gene is dominant and has significant advantages in body measurements such as sacrum height, chest width, and waist height. The C allele at the C4021T locus of IGFBP-3 gene shows an advantage in the body measurement performance. Among the haplotype combinations, H2H2:TGTC is preponderant combination for body size performance, H2H2:TGTC and H1H2:TGCC are preponderant combinations for cashmere production performance, H1H3:GGCC is preponderant combination for milk production performance. It may be a molecular marker for future selection and breeding.

Genomic analysis of indigenous goats in Southwest Asia reveals evidence of ancient adaptive introgression related to desert climate

Understanding how evolutionary pressures related to climate change have shaped the current genetic background of domestic animals is a fundamental pursuit of biology. Here, we generated whole-genome sequencing data from native goat populations in Iraq and Pakistan. Combined with previously published data on modern, ancient (Late Neolithic to Medieval periods), and wild Capra species worldwide, we explored the genetic population structure, ancestry components, and signatures of natural positive selection in native goat populations in Southwest Asia (SWA). Results revealed that the genetic structure of SWA goats was deeply influenced by gene flow from the eastern Mediterranean during the Chalcolithic period, which may reflect adaptation to gradual warming and aridity in the region. Furthermore, comparative genomic analysis revealed adaptive introgression of the KITLG locus from the Nubian ibex ( C. nubiana) into African and SWA goats. The frequency of the selected allele at this locus was significantly higher among goat populations located near northeastern Africa. These results provide new insights into the genetic composition and history of goat populations in the SWA region.

Integrated Analysis of mRNAs and Long Non-Coding RNAs Expression of Oviduct That Provides Novel Insights into the Prolificacy Mechanism of Goat (Capra hircus)

Artificial directional selection has replaced natural selection and resulted in trait differences across breeds in domestic animal breeding. However, the molecular mechanism by which the oviduct regulates litter size remains largely elusive in goats during the follicular phase. Accumulating data have linked lncRNAs to reproductive activities; however, little is known about the modulation mechanism in the oviduct. Herein, RNA-seq was used to measure mRNA and lncRNA expression levels in low- and high-fecundity goats. We observed distinctive differences in mRNA and lncRNA in terms of different kidding numbers and detected the differential expression of 1640 mRNA transcripts and 271 lncRNA transcripts. Enrichment analysis of differentially expressed mRNAs (DEGs) suggested that multiple pathways, such as the AMPK, PI3K–Akt, calcium signaling pathway, oocyte meiosis, ABC transporter, and ECM–receptor interaction pathways, directly or indirectly affected goat reproduction. Additionally, coexpression of differentially expressed lncRNAs (DEL)-genes analysis showed that XLOC_021615, XLOC_119780, and XLOC_076450 were trans-acting as the DEGs ATAD2, DEPDC5, and TRPM6, respectively, and could regulate embryo development. Moreover, XLOC_020079, XLOC_107361, XLOC_169844, XLOC_252348 were the trans-regulated elements of the DEGs ARHGEF2 and RAPGEF6, and the target DEGs CPEB3 of XLOC_089239, XLOC_090063, XLOC_107409, XLOC_153574, XLOC_211271, XLOC_251687 were associated with prolificacy. Collectively, our study has offered a thorough dissection of the oviduct lncRNA and mRNA landscapes in goats. These results could serve as potential targets of the oviduct affecting fertility in goats.

From Mendel laws to whole genetic association study to decipher the swine mulefoot phenotype

The swine mulefoot (SM) is a rare condition characterized by a non-cloven hoof due to the partial or total fusion of the phalanges. No comprehensive study has been conducted to identify associated markers with this phenotype until now. We aimed to characterize the association between SNP and the mulefoot phenotype using a Genome-Wide Association Study (GWAS). An experimental population was produced using a half-sib mating where the male had the mulefoot phenotype and the females (n = 6) had cloven hoofs. The cross resulted in 27 (47%) animals with the mulefoot characteristic and 30 (53%) normal animals, indicating the possible dominant gene action. Animals were further genotyped using the Illumina PorcineSNP50k BeadChip, and SNPs were tested for associations. Twenty-nine SNPs located on the SSC15, SSC4, and SSCX were associated with the mulefoot phenotype (p-value <5 × 10^-5). Six markers were found in the intronic regions of VWC2L, CATIP, PDK3, PCYT1B, and POLA1 genes. The marker rs81277626, on SSC15:116,886,110 bp, is located in the Von Willebrand Factor C Domain (VWC2L), a possible functional candidate gene. The VWC2L is part of a biological process involved with the bone morphogenetic protein (BMP) signaling pathway, previously associated with syndactyly in other species. In conclusion, the identified markers suggest the involvement of the VWC2L gene in the SM phenotype in this population.

Identification of polymorphisms in the MSTN and ADRB3 genes associated with growth and ultrasound carcass traits in Kajli sheep

The aim of this investigation was to find single nucleotide polymorphisms (SNPs) in the myostatin (MSTN) and the beta-3 adrenergic receptor (ADRB3) genes associated with growth and ultrasound carcass traits in Kajli sheep. The five growth traits were birth weight (BWT-EBV), 120-day weight (120DWT-EBV), 180-day weight (180DWT-EBV), 270-day weight (270DWT-EBV), and 365-day weight (365DWT-EBV). The three ultrasound carcass traits were width (WLD) and depth of longissimus dorsi (DLD) and back fat thickness (BFT). The analysis of the MSTN sequence revealed one non-synonymous substitution (c.197T > A) in exon 1, one single nucleotide substitution (c.373 + 18G > T) in intron 1, and one synonymous substitution (c.861T > A) in exon 3. However, there were four single nucleotide synonymous substitutions (c.130C > T, c.294C > G, c.579G > T, and c.654C > G) in exon 1 of the ADRB3 gene. All the SNPs in the MSTN gene, except for c.373 + 18G > T, were in Hardy-Weinberg Equilibrium (HWE). Conversely, none of the SNPs found in ADRB3 were in HWE. Two of the MSTN SNPs (c.197T > A and c.373 + 18G > T) had significant associations with all evaluated growth and ultrasound carcass traits. The SNPs c.130C > T and c.294C > G in ADRB3 were significantly associated with 180DWT-EBV. Collectively, these findings indicate that several SNPs in the studied genes were significantly related to growth and carcass traits in Kajli sheep.

Genetic polymorphism of microsatellite loci in MHC class II exon 2 gene and its association with endoparasitic infestation, predominantly Haemonchus contortus in Salem black goat

MHC gene is highly polymorphic and plays central molecule in immune system in recognition of pathogens and parasites. The present study examined the variability of MHC class II DRB exon 2 gene using microsatellite analysis, and its association with Haemonchus contortus infestation in Salem Black goat population. Animals were naturally exposed to mixed infestation of endoparasites, predominantly Haemonchus contortus. Pooled fecal coproculture and larval identification showed predominant presence of haemonchus (L3) larva. Fecal egg count (FEC) and packed cell volume (PCV) were used as indicator traits. All the three studied loci, OarCP73, DYA, and ODRB1.2, were polymorphic having three, four, and four alleles and four, eight, and nine genotypes, respectively. The loci showed low to moderate values of polymorphic information content. The mean fecal egg count estimates were 477.12 ± 34.14 eggs per gram of feces and the mean PCV values were within the normal range; however, they showed negative correlation with FEC values. All the three microsatellite loci and the effect of genotypes on indicator traits were found to be statistically significant (p ≤ 0.05). The present study will be helpful in selection and breeding of goats for Haemonchosis resistance.

Variation in the ovine FOXP3 gene and its effect on growth traits in Egyptian Barki sheep

The aim of the present study was to detect the FOXP3 gene polymorphisms in Barki sheep at a variable region covering exon 13, intron 13 and the coding sequence in exon 14 and to test the association of these polymorphisms with growth traits. 122 Barki lambs were phenotyped for various growth traits, viz., birth weight (BW), weaning weight (WW), pre-weaning daily gain in weight (ADG1), post-weaning daily gain in weight (ADG2) and marketing bodyweight (MW). The polymerase chain reaction - single-strand conformational polymorphisms (PCR-SSCP) and DNA sequencing methods were used to identify the genetic variants in the FOXP3 gene. The associations between the variation in FOXP3 gene and growth traits were tested using a general linear model. Two variants (F1 and F2 with gene frequencies of 0.64 and 0.36, respectively), and three genotypes (F1F1, F1F2 and F2F2 with frequencies of 0.37, 0.53 and 0.10, respectively) were detected. The association of FOXP3 genotype was significant (p < 0.05) with ADG2 and MW. It is concluded that FOXP3 genotype might be helpful for sheep breeders to produce fast-growing lambs. However, further studies are needed in a large population to confirm the association we found.

Analysis of the eighth intron polymorphism of NR6A1 gene in sheep and its correlation with lumbar spine number

For revealing molecular markers related to the traits of multiple lumbar vertebrae in sheep, we analyze the relationship between NR6A1 gene polymorphism and lumbar vertebrae number traits in Xinjiang Kazakh sheep. Lumbar muscle tissues were collected from 6-lumbar spine (L6) Kazak sheep and 7-lumbar spine (L7) Kazak sheep and the intron-8 of NR6A1 gene was amplified by PCR. The SNP locus was detected by the PCR-SSCP method. One-Way ANOVA and an Independent Chi-square Test is adopted to analyze the genotype association with lumbar spine number variation. There were two SNP loci in the intron-8 of the NR6A1 gene: IVS8-188 and IVS8-281. One-Way ANOVA and Independent Chi-square Test indicated a significant association between IVS8-281 and lumbar spine number. The SNP locus of NR6A1 gene intron 8 (IVS8-281G > A) could play a certain role in the variation of lumbar spine number in Xinjiang Kazakh sheep and demonstrates potential to accelerate the sheep breeding of selection process.

Influence of maternal and additive genetic effects on offspring growth traits in Beetal goat

The purpose of the present study was to obtain estimates of variance components and genetic parameters for direct and maternal effects on various growth traits in Beetal goat by fitting four animal models, attempting to separate direct genetic, maternal genetic and maternal permanent environmental effects under restricted maximum likelihood procedure. The data of 3,308 growth trait records of Beetal kids born during the period from 2004 to 2019 were used in the present study. Based on best fitted models, the direct additive h² estimates were 0.06, 0.27, 0.37, 0.17 and 0.10 for birth weight (BWT), weight at 3 (WT3), 6 (WT6), 9 (WT9) and 12 (WT12) months of age, respectively. Maternal permanent environmental effects significantly contributed for 10% and 7% of total variance for BWT and WWT, respectively, which reduced direct heritability by 40 and 10% for respective traits from the models without these effects. For average daily gain (ADG1) and Kleiber ratios (KR1) up to weaning period (3 months) traits, maternal permanent environmental effects accounted for 7% and 8% of phenotypic variance, respectively, and resulted in a reduction of 6.6% and 5.4% in direct h² of respective traits. For post-weaning traits, the maternal effects were non-significant (p > .05) which indicates diminishing influence of mothering ability for these traits. High and positive genetic correlations were obtained among WT3-WT6, WT6-WT9 and WT9-WT12 with correlations of 0.96 ± 0.25, 0.84 ± 0.23 and 0.90 ± 0.13, respectively. Thus, early selection at weaning age can be practised taking into consideration maternal variation for effective response to selection in Beetal goat.

G1 point mutation in growth differentiation factor 9 gene affects litter size in Sudanese desert sheep

BACKGROUND AND AIM

Sudanese desert sheep encompass different sheep breeds named according to the different Sudanese tribes that rear them such as the Dubasi, Shugor, and Watish sheep. The objectives of this study were to screen for G1 point mutation in the polymorphic growth differentiation factor 9 (GDF9) gene, investigate its association with litter size, and construct the phylogeny of the different tribal breeds that belong to the Sudanese Desert sheep tribal types.

MATERIALS AND METHODS

Genomic DNA was extracted from whole blood of three tribal Desert sheep breeds (Dubasi, Watish, and Shugor) using the guanidine chloride method. Polymerase chain reaction-restriction fragment length polymorphism with HhaI restriction enzyme and sequencing techniques was used for genotyping the GDF9 locus for possible mutations associated with litter size in the three desert sheep tribal types.

RESULTS

G1 mutation in GDF9 caused the replacement of Arginine by Histidine at residue 87. The wild type allele (A) had the highest frequency, whereas the mutant type allele (a) had the lowest in all the sequenced subtypes. The genotype frequencies of the wild type ewes (AA) were higher than the heterozygous (Aa) and the mutant type (aa) frequencies in the three studied desert sheep types. No significant differences were found in the allele frequency between the three tribal types. Litter size was significantly influenced by the genotypes of GDF9 gene, parities, and subtypes (p≤0.01, 0.01, and 0.05, respectively). In the Watish sheep type, heterozygous sheep in their second parity recorded the highest litter size. Sequence alignment of GDF9 gene samples with the database entry indicated that all three tribal types were similar and identical to the reference sequence. The phylogenetic tree revealed that Shugor is the common ancestor of the studied types and Watish is more closely related to Shugor than Dubasi. This result mi ght partly explain the lower reproductive performance of Dubasi compared to Watish and Shugor.

CONCLUSION

The presence of one copy of GDF9 gene increased litter size in the studied Sudanese Desert sheep. This locus may be used as a biomarker for litter size improvement through genotypic selection and allele or gene introgression.

Variation in autosomal and sex-linked genetic effects for growth traits in Markhoz goat using multivariate animal models

The present study was conducted to estimate autosomal and sex-linked genetic parameters by restricted maximum likelihood method using four different multivariate models for growth traits in Markhoz goat. Data were collected over a period of 23 years (1992-2014) from the breeding station of Markhoz goat. The studied growth traits were birth weight (BW), weaning weight (WW), 6-month weight (6WT), 9-month weight (9WT), and 12-month weight (12WT). The best model was determined by Akaike's information criterion. Based on the best model, direct autosomal heritabilities of 0.18, 0.10, 0.12, 0.22, and 0.24 were obtained for BW, WW, 6WT, 9WT, and 12WT, respectively. On the other hand, estimates of direct sex-linked heritability for BW, WW, 6WT, 9WT, and 12WT were 0.02, 0.01, 0.002, 0.03, and 0.04, respectively. The maternal permanent environmental component was remarkable for growth traits. Direct autosomal additive genetic correlations among the traits were positive and varied from 0.11 between BW and 9WT to 0.95 between BW and WW. The positive correlations were also estimated for direct sex-linked additive genetic effect except between BW-6WT (- 0.07) and WW-6WT (-0.19). The result of this study indicated that sex-linked chromosome effect had more considerable influence at post-weaning traits.

Genetic effects of DSCAML1 identified in genome-wide association study revealing strong associations with litter size and semen quality in goat (Capra hircus)

The down syndrome cell adhesion molecule like 1 (DSCAML1), is associated with the development of the nervous system and neurologic diseases. Previous Genome-wide association studies have shown that it is associated with sperm morphology, suggesting it has a critical role in fecundity. In this study, expression profiles of goat DSCAML1 mRNA were analyzed. The results showed that its expression in the testis differ significantly between the mitotic stage and meiotic stage. Three insertion/deletion (indel) variants of goat DSCAML1 were determined in the Shaanbei White Cashmere Goat (SWCG, n = 2162). Based on the association analysis, two indels (P2-16bp, P14-15bp) were significantly related to sperm quality (sperm motility and sperm density) in male goat and three loci were markedly related to the first-birth litter size in female goat (P = 4.0 × 10^-6; P = 1.0 × 10^-6; P = 4.7 × 10^-2). In male goats, the different genotypes of P2-16bp and P14-15bp revealed a noticeable effect on the expression of DSCAML1. Moreover, the effects observed in the first-birth litter followed a similar trend, which may provide the basis for further research of DSCAML1 gene function and marker assisted selection (MAS) programs to improve reproductive traits.