一种新的家蚕体形突变体--短体蚕(Sq)的遗传分析与基因定位

Genetic analysis and gene localization of a new body shape mutant,Squab(Sq),in the silkworm,Bombyx mori

作为重要经济昆虫和鳞翅目昆虫模式的家蚕Bombyxmori,其突变体是生理学、遗传学、功能基因组学等研究的宝贵资源。作者在家蚕资源保存和遗传分析中发现一种新的体形突变体——短体蚕(Squab,Sq),其特征是:杂合体(Sq/+)成活,蚕体长只有正常型的约4/5,腹中部略肥大,胸部稍狭小;纯合体(Sq/Sq)胚胎期致死。遗传分析结果表明该突变为显性遗传。通过与各染色体标记基因进行连锁分析,发现突变基因Sq在家蚕第14染色体上;通过与同一染色体上的标记基因青熟油蚕基因(oa)、不洁蚕基因(Di)进行三点测验,将Sq定位在家蚕连锁图谱第14连锁群的34.6cM位点,表示为Sq(14-34.6)。本研究结果为深入研究和利用该突变体奠定了重要基础。

The silkworm, Bombyx mori, is an important economic insect and a model for Lepidoptera insects; the mutants of silkworm are the valuable resources for physiology, genetics and functional genomics. We discovered a new body shape mutant named Squab （Sq） during the conservation and genetic analysis of the silkworm resources. The heterozygote （ Sq/＋ ） could survive, and the length of mutant is just about four-fifths of the normal and is characterized by slight fat abdomen in the middle region and a little narrow thorax; the homozygote （Sq/Sq） is embryonic lethal. The genetic analysis showed that it was controlled by dominant mutant gene. It is confirmed that the mutant gene Sq belongs to the 14th linkage group by crossing it with the marker genes for each linkage group. Three-point test among aojuku translucent （oa）, dirty （Di） and Sq showed that the gene locus of Sq is at 34.6 cM on the 14th linkage group in silkworm linkage map. This study has important significance for further research and utilization of this mutant.