基于40K SNP液相芯片的花鲈家系亲权鉴定及群体遗传分析

Parentage identification and population genetic analysis of Lateolabrax maculatus families based on 40K SNP liquid-phase array

  • 摘要: 【目的】 从鉴别准确率和成功率等方面评价采用基因芯片进行花鲈亲权鉴定的可行性,构建精准的分子溯源体系,为花鲈种质资源保护、近交防控及其分子育种体系构建提供理论依据。【方法】 采集同池混养的5个家系(F1、F5、F6、F7和F8)83尾花鲈个体,通过自主研发的花鲈40K SNP液相芯片进行亲权鉴定和群体遗传分析,系统评估不同花鲈家系的遗传特征及基因芯片技术在亲权鉴定中的适用性。【结果】 5个花鲈家系的观测杂合度(Ho)介于0.2423~0.3725,平均为0.3273;期望杂合度(He) 介于0.2476~0.3238,平均为0.2913;多态信息含量(PIC)介于0.2045~0.2575,平均为0.2349,除了F7家系外,其余家系均为低度多态性。F6家系与F1家系和F7家系间为高度遗传分化遗传分化系数(Fst >0.15,F7家系与F8家系间为低度遗传分化(Fst<0.05),其余家系间则为中度遗传分化(0.05<Fst<0.15)。基于原始系谱数据的群体遗传结构分析发现,5个花鲈家系可划分为6个类群,以F6家系较混杂,其群体内的遗传多样性较丰富。在双亲已知条件下,5个花鲈家系的双亲累积鉴定率为88.00%,实际双亲鉴定率为65.33%,单亲累积鉴定率为88.00%,实际单亲鉴定率为66.67%,孟德尔错误率为0.44%~0.73%(<0.90%)。基于系谱梳理后的群体遗传分析结果显示,5个花鲈家系最终聚类为6个遗传类群,与基于原始系谱数据的群体遗传分析结果相互印证。亲缘关系分析结果表明,同一家系内个体间的亲缘关系较紧密,而不同家系个体间的亲缘关系相对较疏远。【结论】 基于40K SNP液相芯片的亲权鉴定与群体遗传分析结果显示,同池混养5个花鲈家系群体遗传多样性呈中低度多态性特征,家系间遗传分化明显,亲缘关系较疏远,最终划分为6个遗传类群。说明利用基因芯片技术评估不同花鲈家系间的群体遗传结构特征和亲缘关系是一种可行的方法,能准确揭示家系间的遗传关系及系谱结构,为花鲈种质资源管理和家系纯度控制提供技术支撑。

     

    Abstract: 【Objective】 To evaluate the feasibility of parentage identification in spotted seabass (Lateolabrax maculatus) using a gene array in terms of accuracy and success rate, and to establish a precise molecular traceability system, which could provide theoretical basis for germplasm resource conservation, inbreeding control, and the development of a molecular breeding system for Lateolabrax maculatus.【Method】 Eighty-three Lateolabrax maculatus individuals from five families (F1, F5, F6, F7, and F8) cultured in the same pond were collected. Parentage identification and population genetic analysis were performed using a self-developed 40K liquid-phase SNP array for Lateolabrax maculatus to systema-tically evaluating the genetic characteristics of different Lateolabrax maculatus families and the applicability of gene array technology in parentage identification.【Result】 The observed heterozygosity (Ho) of 5 Lateolabrax maculatus families ranged from 0.2423 to 0.3725, with average of 0.3273; expected heterozygosity (He) from ranged 0.2476 to 0.3238, with average of 0.2913; and PIC ranged from 0.2045 to 0.2575, with average of 0.2349, indicating generally low polymorphism for the families except F7. Genetic differentiation was high between F6 and F1 and between F6 and F7 genetic differentiation coefficient (Fst) > 0.15, genetic differentiation was low between F7 and F8 (Fst < 0.05), and genetic differentiation was moderate between other family pairs (0.05 < Fst < 0.15). Population genetic structure analysis based on raw pedigree data revealed that the five families of Lateolabrax maculatus could be divided into six genetic clusters, with F6 showing higher admixture and greater genetic diversity within the group. Under known-parent conditions, the cumulative identification rate of the five families of Lateolabrax maculatus for both parents reached 88.00%, with an actual identification rate of 65.33%; the cumulative single-parent identification rate was 88.00%, with an actual rate of 66.67%. The Mendelian error rate ranged from 0.44% to 0.73% (< 0.90%). The population genetic analysis based on pedigree correction showed that the five families of Lateolabrax maculatus were ultimately clustered into six genetic groups, consistent with the results obtained from the analysis based on raw pedigree data. Kinship analysis indicated that individuals within the same family were more closely related, whereas those from different families exhibited relatively distant relationships.【Conclusion】 Using a 40K SNP liquid-phase array, parentage identification and population genetic analysis have been conducted. The results reveal moderate to low levels of genetic polymorphism for the five Lateolabrax maculatus families reared in a common pond, significant genetic differentiation and relatively distant kinship among families, and the the five families are ultimately divided into six genetic clusters. These findings demonstrate that gene array technology is a reliable approach for evaluating population genetic structure and kinship among Lateolabrax maculatus families, which can accurately elucidate their genetic relationships and pedigree structure, and provide technical support for Lateolabrax maculatus germplasm resource management and family purity control.

     

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