ACADEMIA Letters A review on Genome evolution of plant parasitic Nematodes Krishanu Singh Shweta Yadav Poornima Maurya Abstract In terms of the numbers of individuals, nematodes are the most abundant type of animal on earth.So far 25,000 species have been classifed, and there could be 100 mil- lion species . This abundance results from their ability to adapt, as well as their small size, resistant cuticle, and simple body plan. Small changes to their body plan have al- lowed invasion of many diferent habitats. Nematodes live in hot springs, polar ice, soil, fresh and salt water, and as parasites of plants, vertebrates, insects, and other nematodes . This evolutionary plasticity, which hints at an underlying genetic plasticity, has long fascinated biologists. In. Some of the major evolutionary forces that have shaped ne- matode genomes: how selection seems to have acted to preserve operons and clusters of co-expressed genes; how the involvement of the X and Y chromosomes in sex determi- nation may have afected the evolution of their sequence and structure ; how diferent reproductive strategies may have afected the evolution of chromosome number, struc- ture, and sequence ; and how a large number of novel genes have arisen and acquired new functions, probably enabling adaptation to new environmental niches, such as parasitism. INTRODUCTION Nematoda is one of the most numerous and diverse phyla of animals. To date, more than 27,000 species have been described and the total number of species is estimated to be more than a million. The majority of species are free-living and feed on bacteria, fungi, or algae, but Academia Letters, July 2021 Corresponding Author: Krishanu Singh, krishanusingh444@gmail.com Citation: Singh, K., Yadav, S., Maurya, P. (2021). A review on Genome evolution of plant parasitic Nematodes. Academia Letters, Article 1527. https://doi.org/10.20935/AL1527. 1 ©2021 by the authors — Open Access — Distributed under CC BY 4.0