Evolution of sex chromosomes in grass moths (Lepidoptera: Crambidae)

• Grant number: 17/09731-9
• Support Opportunities: Scholarships abroad - Research
• Start date: March 09, 2018
• End date: March 08, 2019
• Field of knowledge: Biological Sciences - Genetics - Animal Genetics
• Principal Investigator: Diogo Cavalcanti Cabral de Mello
• Grantee: Diogo Cavalcanti Cabral de Mello
• Host Investigator: Frantisek Marec
• Host Institution: Instituto de Biociências (IB). Universidade Estadual Paulista (UNESP). Campus de Rio Claro. Rio Claro , SP, Brazil
• Institution abroad: Czech Academy of Sciences (CAS), Czech Republic

Abstract

The family Crambidae (grass moths) includes approximately 11,000 species and thus represents one of the largest families of the insect order Lepidoptera. Several species of this family are particularly well known due to severe economic losses in agricultural production. In Brazil, some Crambidae species such as Diatraea saccharalis, D. flavipennella and Omiodes indicata have been causing significant agricultural losses, especially in sugarcane and soybean cultures. In addition, there are invasive species with recognized potential to enter Brazil, such as Chilo partellus. Despite the importance of crambid moths very is little is known about their genome architecture, because only a few cytogenetic studies were performed. For example, the knowledge of sex chromosomes is restricted to two Ostrinia species, O. scapulalis and O. nubilalis and only the chromosome numbers are known for other few species. Some species have a reduced diploid number, suggesting the occurrence of chromosomal fusions and possibly also neo-sex chromosomes, presumably represented by large sex chromosomes. In Lepidoptera, such neo-sex chromosomes can play important role in evolution, like reported for the neo-Z chromosome in the family Tortricidae that have arisen through fusion of the ancestral Z chromosome with an autosome, resulting in the sex-linkage of several major genes involved in insecticide resistance and detoxification of plant secondary metabolites. The sex-linkage of these genes greatly increased adaptive potential and consequently the radiation and speciation of this group. Bearing these information in mind the aim of this proposal is to verify the occurrence of neo-sex chromosomes in Crambidae and whether they could play a role in the evolution of this species-rich family of Lepidoptera. This aim will be addressed by using a combination of chromosomal, molecular, NGS and bioinformatic analyses. (AU)