Studies on Basic Chromosome Number, Ploidy Level, Chromosomal Association and Configuration and Meiotic Behavior in Mulberry (Morus Spp.)

Mulberry leaves are primary food for silkworm, Bombyx mori L. to feed silkworms and harvest quality silk cocoons. Mulberry belongs to family Moraceae and includes 60 species found distributed in both Hemisphere. In mulberry, chromosome numbers are varies from 2n = 28 to 22n = 308 (Diploid to Decosoploid) with ploidy level x to 22x. Based on chromosome numbers and meiotic behaviors x = 14 has been considered as basic chromosome numbers of the genus. In the present study, two diploids, two uneuploids, two triploids and two teteraploids mulberry varieties were selected for detailed chromosomal numbers and meiotic behaviors belongs to three species, namely Morus indica, Morus alba and Morus latifolia. Varieties, Vishaala and Kosen were diploids with 2n = 2x = 28 chromosomes and varieties Ber-S1 and S13 were uneuploids with 2n = 30 chromosomes belongs Morus indica. Varieties NAO Khurkul and KPG-1 were triploids with 2n = 3x = 42 chromosomes belongs to Moru alba and varieties Kokuso and Icheihei were tetraploids with 2n = 4x = 56 chromosomes. Diploids and uneuploids were showed normal meiosis with high pollen fertility and triploids and teteraploids were showed abnormal meiosis with low pollen fertility, due to virtue of higher ploidy level have been discussed in this chapter.

Contribution of Environmental Constituents in the Genomic Disruption of Cytokeratins

Cytokeratins are keratinous protein and assist cells to reduce mechanical stress on the intracytoplasmic layer of epithelial tissue. There are several unspecified mutations in the epithelial layer that may induces by environmental mutagens and pathogens. The unspecified mutations in the epithelium surface also disrupt biology of skin at multiple different levels and cause innate keratinizing disorders. These serve as a root generator of neurohormones and neuropeptides which mainly partake in the disruption. Generally, all 54 unique genes of human keratin partake in mutations and cause cutaneous tissue fragility, skin hypertrophic, and malignant transformation. In this chapter, unspecific factors that involved in the pathogenesis of skin diseases and the ways by which such keratin changes might harness to alleviate different skin conditions are also included. Consequently, the contribution of environmental changes in the frontier of mutations or misregulations of the cytokeratin genes, is also cited here.