ICAR-Central Institute of Freshwater Aquaculture, Kausalyaganga, Bhubaneswar, Odisha, 751002, India.
ICAR-Central Institute of Fisheries Education, Panch Marg, Versova, Mumbai, Maharashtra, 400 061, India.
Mol Biol Rep. 2024 Aug 21;51(1):926. doi: 10.1007/s11033-024-09866-y.
Captive breeding, along with artificial selection can significantly impact population structure by influencing allele frequencies and driving populations towards specific adaptation. Selective sweeps are powerful forces in shaping genetic variation within populations and can drive rapid spread of beneficial alleles while simultaneously reducing genetic diversity in localized regions of the genome. The present work was undertaken to assess the genetic structure and consequences of artificial selection in 10 generation of genetically improved rohu by comparing with wild populations.
The present study used 11,022 high-quality genome wide SNPs to compare the population genetic structure and signatures of selection between Jayanti rohu population and its wild counterpart. Outlier analysis revealed presence of 14 adaptive SNPs, out of which 5 were classified to be under decisive selection pressure. Notably, Jayanti rohu (JR) displayed 297 private alleles exclusive to its population. Chromosomes 7 and 16 emerged as potential hotspots containing a majority of the identified SNPs. Structure and principal component analysis revealed two distinct clusters, effectively distinguishing the JR and wild rohu populations. Phylogenetic analysis indicated a separate cluster of JR population distant from wild groups.
The results of present study shall help in elucidating patterns of genetic variation and characterizing selection signatures associated with captive bred and natural populations of rohu. The genomic resources generated through this work shall be helpful in improving the traceability of selectively bred germplasm for developing future strategies of genetic management.
圈养繁殖和人工选择可以通过影响等位基因频率和促使种群朝着特定的适应性方向发展，从而显著影响种群结构。选择压力是塑造种群内遗传变异的强大力量，可以在基因组的局部区域快速传播有益等位基因，同时降低遗传多样性。本研究旨在通过与野生种群进行比较，评估人工选择对经过 10 代遗传改良的罗非鱼的遗传结构和后果。
本研究使用了 11022 个高质量的全基因组 SNP，比较了 Jayanti 罗非鱼种群及其野生种群的群体遗传结构和选择信号。异常值分析显示，存在 14 个适应性 SNP，其中 5 个被归类为决定性选择压力。值得注意的是，Jayanti 罗非鱼（JR）显示出 297 个仅存在于其种群中的特有等位基因。第 7 号和第 16 号染色体成为包含大多数已识别 SNP 的潜在热点。结构和主成分分析显示出两个不同的聚类，有效地将 JR 和野生罗非鱼种群区分开来。系统发育分析表明，JR 种群与野生群体分离形成一个单独的聚类。
本研究的结果将有助于阐明遗传变异模式，并描述与圈养和自然罗非鱼种群相关的选择特征。通过这项工作产生的基因组资源将有助于提高选择性繁殖种质的可追溯性，为制定未来的遗传管理策略提供帮助。
