Insects produce silk for a range of purposes. In the Lepidoptera, silk is utilized as a material for cocoon production and serves to protect larvae from adverse environmental conditions or predators. Species in the Sa...Insects produce silk for a range of purposes. In the Lepidoptera, silk is utilized as a material for cocoon production and serves to protect larvae from adverse environmental conditions or predators. Species in the Saturniidae family produce an especially wide variety of cocoons, for example, large, golden colored cocoons and those with many small holes. Although gene expression in the silk gland of the domestic silkworm （Bombyx mori L.） has been extensively studied, considerably fewer investigations have focused on members of the saturniid family. Here, we established expression sequence tags from the silk gland of the eri silkworm （Samia ricini）, a saturniid species, and used these to analyze gene expression. Although we identified thefibroin heavy chain gene in the established library, genes for other major silk proteins, such asfibroin light chain andfibrohexamerin, were absent. This finding is consistent with previous reports that these latter proteins are lacking in saturniid silk. Recently, a series offibrohexamerin-like genes were identified in the Bombyx genome. We used this information to conduct a detailed analysis of the library established here. This analysis identified putative homologues of these genes. We also found several genes encoding small silk protein molecules that are also present in the silk of other Lepidoptera. Gene expression patterns were compared between eri and domestic silkworm, and both conserved and nonconserved expression patterns were identified for the tested genes. Such differential gene expression might be one of the major causes of the differences in silk properties between these species. We believe that our study can be of value as a basic catalogue for silk gland gene expression, which will yield to the further understanding of silk evolution.展开更多
为合理利用木薯叶,避免浪费资源,在蓖麻蚕的不同龄期以木薯叶、蓖麻叶为组合饲料进行饲养,比较其饲养成绩、老熟蚕虫体、蛹及蚕茧的质量,结果表明:以1~5龄全龄饲喂蓖麻叶(CK)的蓖麻蚕饲养成绩最好,全龄经过为37 d 2 h,1~3龄蓖麻叶、4~5...为合理利用木薯叶,避免浪费资源,在蓖麻蚕的不同龄期以木薯叶、蓖麻叶为组合饲料进行饲养,比较其饲养成绩、老熟蚕虫体、蛹及蚕茧的质量,结果表明:以1~5龄全龄饲喂蓖麻叶(CK)的蓖麻蚕饲养成绩最好,全龄经过为37 d 2 h,1~3龄蓖麻叶、4~5龄木薯叶处理(T1)的饲养成绩次之,1~5龄全木薯(T3)叶饲养时间最长,全龄经过为41 d 10 h;老熟蚕虫体质量方面,1~5龄全蓖麻叶处理(CK)的蚕体长、体宽表现最优,1~5龄全木薯叶处理(T3)老熟蚕体重最大,1~3龄蓖麻叶、4~5龄木薯叶处理(T1)的蓖麻蚕次之,与前者比较无显著性差异;蛹的质量及蚕茧质量方面,1~5龄全木薯叶处理(T3)的雌蛹蛹长、蛹宽、蛹重,雄蛹的蛹宽、蛹高、蛹重,雌蚕茧质量表现最优,雄茧全茧量第1,而1~3龄蓖麻叶、4~5龄木薯叶处理(T1)的以上各指标表现同样优秀,多项指标位列第2,两处理各指标比较均无显著性差异,综合而言,结合饲养成绩,适宜在云南推广1~3龄蓖麻叶、4~5龄木薯叶(T1)的蓖麻蚕饲养组合。展开更多
文摘Insects produce silk for a range of purposes. In the Lepidoptera, silk is utilized as a material for cocoon production and serves to protect larvae from adverse environmental conditions or predators. Species in the Saturniidae family produce an especially wide variety of cocoons, for example, large, golden colored cocoons and those with many small holes. Although gene expression in the silk gland of the domestic silkworm （Bombyx mori L.） has been extensively studied, considerably fewer investigations have focused on members of the saturniid family. Here, we established expression sequence tags from the silk gland of the eri silkworm （Samia ricini）, a saturniid species, and used these to analyze gene expression. Although we identified thefibroin heavy chain gene in the established library, genes for other major silk proteins, such asfibroin light chain andfibrohexamerin, were absent. This finding is consistent with previous reports that these latter proteins are lacking in saturniid silk. Recently, a series offibrohexamerin-like genes were identified in the Bombyx genome. We used this information to conduct a detailed analysis of the library established here. This analysis identified putative homologues of these genes. We also found several genes encoding small silk protein molecules that are also present in the silk of other Lepidoptera. Gene expression patterns were compared between eri and domestic silkworm, and both conserved and nonconserved expression patterns were identified for the tested genes. Such differential gene expression might be one of the major causes of the differences in silk properties between these species. We believe that our study can be of value as a basic catalogue for silk gland gene expression, which will yield to the further understanding of silk evolution.
文摘为合理利用木薯叶,避免浪费资源,在蓖麻蚕的不同龄期以木薯叶、蓖麻叶为组合饲料进行饲养,比较其饲养成绩、老熟蚕虫体、蛹及蚕茧的质量,结果表明:以1~5龄全龄饲喂蓖麻叶(CK)的蓖麻蚕饲养成绩最好,全龄经过为37 d 2 h,1~3龄蓖麻叶、4~5龄木薯叶处理(T1)的饲养成绩次之,1~5龄全木薯(T3)叶饲养时间最长,全龄经过为41 d 10 h;老熟蚕虫体质量方面,1~5龄全蓖麻叶处理(CK)的蚕体长、体宽表现最优,1~5龄全木薯叶处理(T3)老熟蚕体重最大,1~3龄蓖麻叶、4~5龄木薯叶处理(T1)的蓖麻蚕次之,与前者比较无显著性差异;蛹的质量及蚕茧质量方面,1~5龄全木薯叶处理(T3)的雌蛹蛹长、蛹宽、蛹重,雄蛹的蛹宽、蛹高、蛹重,雌蚕茧质量表现最优,雄茧全茧量第1,而1~3龄蓖麻叶、4~5龄木薯叶处理(T1)的以上各指标表现同样优秀,多项指标位列第2,两处理各指标比较均无显著性差异,综合而言,结合饲养成绩,适宜在云南推广1~3龄蓖麻叶、4~5龄木薯叶(T1)的蓖麻蚕饲养组合。
