Design and validation of high-density SNP array of goats and population stratification of Indian goat breeds

Genomic advancements in goat breeding: enhancing productivity, disease resistance, and sustainability in India's rural economy

Goats are vital to the rural economy of India, contributing significantly to livelihoods, nutrition, and agricultural sustainability. With a population of 148.88 million, India holds the world's largest goat population, comprising 41 recognized indigenous breeds. These goats provide milk, meat, and fiber, particularly in marginal environments. The genomic advancements in goat research have revolutionized the understanding of genetic diversity, adaptation, and trait improvement. Whole-genome sequencing (WGS), single nucleotide polymorphism (SNP) arrays and transcriptomics have unveiled genetic markers associated with production, disease resistance, and reproductive traits. Genomic tools such as the Illumina Goat SNP50K BeadChip and high-throughput sequencing technologies have facilitated the identification of selection signatures and quantitative trait loci (QTL), influencing economically important traits like milk yield, meat quality, and prolificacy. Notably, genes such as DGAT1, GHR, BMPR1B, and HSP70 have been linked to production efficiency, reproductive performance, and climate resilience. Genome-wide association studies (GWAS) and genomic selection (GS) have enabled precision breeding, enhancing genetic gains and reducing inbreeding risks. The application of RNA sequencing has provided insights into gene expression patterns governing lactation, growth, and reproductive efficiency. Epigenomic studies, focusing on DNA methylation and histone modifications, have highlighted regulatory mechanisms underpinning prolificacy and muscle development. Conservation genomics has played a pivotal role in safeguarding native breeds by assessing genetic diversity and mitigating inbreeding depression. Indicine goat breeds, such as Jamunapari, Beetal, Barbari, and Black Bengal, exhibit unique genetic adaptations to diverse agro-climatic conditions, emphasizing the need for their conservation. Emerging technologies, including CRISPR-Cas9 gene editing, hold promise for precision breeding to enhance productivity and disease resistance. Integrating genomics with artificial intelligence (AI) and big data analytics is poised to revolutionize goat breeding and management. Future efforts should focus on expanding genomic databases, developing breed-specific reference genomes, and promoting genomic literacy among farmers to ensure sustainable goat production and improve rural livelihoods in India.

Development and validation of a high-density SNP chip tailored for genomic analysis in Indian backyard chickens

1. Indian backyard chicken breeds are well adapted to local climatic conditions and possess distinct genetic characteristics, necessitating a dedicated SNP chip to address their unique genetic diversity, breed identification and conservation needs. In this study, a high-density SNP chip, Axiom_Kukkut was developed with SNP markers derived from genomes of 16 indigenous chicken breeds, Red Jungle Fowl and White Leghorn.2. A total of 622,376 markers and an inter-marker distance of 1.9 kb, the Axiom_Kukkut provided a denser marker distribution compared to existing arrays. The chip was validated by genotyping a set of samples from diverse Indian chicken breeds. All the SNPs were used for validation. An average call rate of 99.92% and 91.28%, as high resolution polymorphic markers, demonstrated the high precision of the designed array.3. Population stratification analysis revealed high genetic diversity and distinct linkage disequilibrium patterns among various breeds. Multivariate principal component analysis confirmed the genetic distinctiveness of Red Jungle Fowl and Uttara, suggesting low genetic diversity due to geographic isolation or specific breeding practices.4. The customised SNP chip allows a multitude of possibilities, including applications in genome-wide association analysis, identification of selection signatures, population genetics and breed improvement programmes for Indian chicken. Continued refinement will expand its utility to include exotic and commercial breeds as well, enhancing its overall applicability across a wider range of chicken populations.

Design and verification of a 25 K multiple-SNP liquid-capture chip by target sequencing for dairy goat

BACKGROUND

In the genetic breeding research of dairy goats, traditional genotyping methods have limitations, and existing goat chips have shortcomings in functional loci and other aspects, which cannot meet the precise genetic analysis needs of dairy goats. Genotyping by Target Sequencing (GBTS) in the new generation of sequencing technology provides the possibility to solve these problems.

RESULTS

A large number of candidate SNP sites related to important economic traits in dairy goats were identified through various analysis and screening methods. The chip ultimately retained 27,396 SNP sites for probe design, which can detect 46,459 SNPs. The site distribution is uniform, and the sequencing data efficiency, base quality, alignment rate, and other indicators are good. The chip SNP detection rate is high and the heterozygosity of gene typing is reasonable. GWAS was performed on 200 dairy goats for litter size and birth weight traits, and multiple genome-wide significantly related SNPs and related genes (litter size trait: SCAP, PTPN23, KIF9, ANTXRL, and GRID1. birth weight trait: NALCN, LRRN2, TMEM132D, COL5A2, and HS3ST1) were detected.

CONCLUSION

The 25 K multiplex SNP liquid phase capture chip designed in this study has excellent performance and is of great value for genetic research and breeding of dairy goats, providing strong support for the development of the dairy goat industry.

Review on camel genetic diversity: ecological and economic perspectives

Camels, known as the "Ship of the Desert," play a vital role in the ecosystems and economies of arid and semi-arid regions. They provide meat, milk, transportation, and other essential services, and their resilience to harsh environments makes them invaluable. Despite their similarities, camel breeds exhibit notable differences in size, color, and structure, with over 40 million camels worldwide. This number is projected to increase, underscoring their growing significance. Economically, camels are crucial for food production, tourism, and trade, with camel racing being particularly significant in Arab countries. Their unique physiological traits, such as low disease susceptibility and efficient water conservation, further enhance their value. Camel products, especially meat and milk, offer substantial nutritional and therapeutic benefits, contributing to their high demand. Genetic diversity studies have advanced our understanding of camels' adaptation to extreme environments. Functional genomics and whole-genome sequencing have identified genes responsible for these adaptations, aiding breeding programs and conservation efforts. High-throughput sequencing has revealed genetic markers linked to traits like milk production and disease resistance. The development of SNP chips has revolutionized genetic studies by providing a cost-effective alternative to whole-genome sequencing. These tools facilitate large-scale genotyping, essential for conserving genetic diversity and improving breeding strategies. To prevent the depletion of camel genetic diversity, it is crucial to streamline in situ and ex situ conservation efforts to maintain their ecological and economic value. A comprehensive approach to camel conservation and genetic preservation, involving advanced genomic technologies, reproductive biotechniques, and sustainable management practices, will ensure their continued contribution to human societies.

Advancing equine genomics: the development of a high density Axiom_Ashwa SNP chip for Indian horses and ponies

The unique horse and pony breeds of India are declining at an alarming rate. These horses have been integral to the Indian culture and customs for centuries and represent a valuable genetic resource. It is imperative to harness the potential of this equine genetic resource that urgently needs conservation. The study highlights the design and development of a high density SNP array, the Axiom_Ashwa to aid in the genetic analysis and conservation efforts for Indian horse and pony breeds. With 613,950 SNPs, this chip offers extensive genome coverage having an average inter-marker distance of 4 kb. The Axiom_Ashwa has been validated on a larger set of diverse indigenous samples as well as Thoroughbreds, demonstrating a high call rate of 99.4% and robustness for genotyping indigenous breeds. Linkage disequilibrium (LD) analysis showed higher average LD in Indian breeds compared to exotic breeds, suggesting a limited effective population size and recent bottlenecks. Phylogenetic and population stratification analyses using PCA and DAPC clearly distinguished horses, ponies and Thoroughbreds, confirming the efficacy of the Axiom_Ashwa chip. These findings underscore the urgent need for conservation efforts for Indian horse breeds, which have experienced significant drop in population size. The Axiom_Ashwa SNP chip offers advantages such as cost-effectiveness and high throughput, providing a more accurate genetic representation of Indian horses.

Development and validation of the Axiom-MaruPri SNP chip for genetic analyses of domesticated old world camelids

Camels play a crucial socio-economic role in sustaining the livelihoods of millions in arid and semi-arid regions. They possess remarkable physiological attributes which enable them to thrive in extreme environments, and provide a source of meat, milk and transportation. With their unique traits, camels embody an irreplaceable source of untapped genomic knowledge. This study introduces Axiom-MaruPri, a medium-density SNP chip meticulously designed and validated for both Camelus bactrianus and Camelus dromedarius. Comprising of 182,122 SNP markers, derived from the re-sequenced data of nine Indian dromedary breeds and the double-humped Bactrian camel, this SNP chip offers 34,894 markers that display polymorphism in both species. It achieves an estimated inter-marker distance of 14 Kb, significantly enhancing the coverage of the camel genome. The medium-density chip has been successfully genotyped using 480 camel samples, achieving an impressive 99 % call rate, with 96 % of the 182,122 SNPs being highly reliable for genotyping. Phylogenetic analysis and Discriminant Analysis of Principal Components yield clear distinctions between Bactrian camels and dromedaries. Moreover, the discriminant functions substantially enhance the classification of dromedary camels into different breeds. The clustering of various camel breeds reveals an apparent correlation between geographical and genetic distances. The results affirm the efficacy of this SNP array, demonstrating high genotyping precision and clear differentiation between Bactrian and dromedary camels. With an enhanced genome coverage, accuracy and economic efficiency the Axiom_MaruPri SNP chip is poised to advance genomic breeding research in camels. It holds the potential to serve as an invaluable genetic resource for investigating population structure, genome-wide association studies and implementing genomic selection in domesticated camelid species.

Evaluation of the Genetic Diversity and Population Structure of Four Native Pig Populations in Gansu Province

Indigenous pig populations, including Bamei pigs (BM), Hezuo pigs (HZ), Huixian Qingni Black pigs (HX), and Minxian Black pigs (MX) in Gansu Province, live in a particular climate and a relatively closed geographical environment. These local pig breeds are characterized by excellent characteristics (e.g., cold tolerance, robust disease resistance, and superior meat quality). In the past few years, pig populations in Gansu Province have decreased significantly because of their poor lean meat percentage, high fat content, and slow growth rate. Maintaining the diversity of these four breeds can act as a source of new alleles to be incorporated into commercial breeds which are more susceptible to disease and less adaptable to changing conditions because of inbreeding. Genomic data analysis is adequate for determining the genetic diversity and livestock breeding population structure, even in local pig populations. However, the genetic diversity and population structure of the four native pig populations in Gansu Province are still unknown. Thus, we used "Zhongxin-I" porcine chip for the SNP detection of 102 individuals living on four pig conservation farms. A total of 57,466 SNPs were identified among the four pig breeds. The linkage disequilibrium (LD) plot showed that MX had the highest level of LD, followed by BM, HZ, and HX. The observed heterozygosity (Ho) in all four populations was higher than the expected heterozygosity (He). A principal component analysis (PCA) demonstrated that the four local pig populations were isolated. The identity displayed by the state matrix and G matrix heat map results indicated that small numbers of individuals among the four pig breeds had a high genetic distance and weak genetic relationships. The results of the population genetic structure of BM, HZ, HX, and MX pigs showed a slight genetic diversity loss. Our findings enabled us to better understand the genome characteristics of these four indigenous pig populations, which will provide novel insights for the future germplasm conservation and utilization of these indigenous pig populations.