Silkworm Genetics and Chemical Mutagenesis

Dose-Dependent Minimisation of Cytogenetic Toxicity of Endosulfan(an Organochlorine Pesticide) by Vitamin C.

“…Roles of other biological responses such as elimination of abnormality bearing cells by their suicidal self-killing ("apoptosis" of Potten 1983), and filling in of the void so created by compensatory division among the remaining "resistant" cells (Kondo et al 1984) might also be responsible for an apparently protective effect of ascorbic acid as presently observed (Tazima 1984). The protective effect of vitamic C, though real and statistically significant, could also be the result of kinetic perturbation in the various lines of differentiating elements and many stages of differentiation of cells in a heterogeneous population of bone marrow tissue (Savage 1990).…”

Genetic mapping of resistance to Bacillus thuringiensis toxins in diamondback moth using biphasic linkage analysis

“…An efficient way to overcome this problem is to exploit the biphasic nature of genetic linkage found in Lepidoptera (11)(12)(13). Any two loci on the same chromosome are absolutely linked in females, because no crossing-over occurs during oogenesis and the loci cannot recombine.…”

Carotenoid silk coloration is controlled by a carotenoid-binding protein, a product of the Yellow blood gene

“…Larvae of mutants homozygous for the recessive ϩ Y allele inadequately absorb dietary carotenoids, resulting in colorless hemolymph and white cocoons. At least six genes that control carotenoid-based color function only when they coexist with the dominant Y allele (6,7), suggesting that the Y gene plays a central role in cocoon color pigmentation.…”

“…These pigments are absorbed from dietary mulberry leaves, transferred from the midgut to the silk gland via the hemolymph, and accumulated in the silk fiber (4). Since the genetic research of Coutagne in 1903 (5), 15 genes (loci) that control cocoon color have been identified (6,7) (also see www.shigen.nig.ac.jp/silkwormbase/index.jsp). To date, however, none of these genes has been cloned.…”