Meiosis in scorpions (Arachnida): model to understand the evolution in species wit...
| Grant number: | 13/11840-0 |
| Support type: | Scholarships in Brazil - Doctorate |
| Effective date (Start): | October 01, 2013 |
| Effective date (End): | July 31, 2017 |
| Field of knowledge: | Biological Sciences - Zoology - Morphology of Recent Groups |
| Principal Investigator: | Marielle Cristina Schneider |
| Grantee: | Viviane Fagundes de Mattos |
| Home Institution: | Instituto de Biociências (IB). Universidade Estadual Paulista (UNESP). Campus de Rio Claro. Rio Claro , SP, Brazil |
| Associated research grant: | 11/21643-1 - Meiosis in scorpions (Arachnida): model to understand the evolution in species with achiasmate chromosomes, AP.JP |
Abstract Buthidae is considered phylogenetically basal within the order Scorpiones and presents the highest diversity of species taxonomically described. Cytogenetically, less than 5% of the described buthids were analysed, which exhibited very interesting chromosomal characteristics that can constitute models for understanding of the mechanism of chromosome evolution within the group. The Buthidae scorpions present a high inter or intraindividual and/or inter or intraspecific variability of diploid number and chromosome multivalent associations during the prophase I, which were originated by reciprocal translocations or fission/fusion rearrangements. Moreover, the buthids show holocentric chromosomes, and synaptic and achiasmatic chromosomal behaviour in meiosis, which make it possible to investigate about the mechanisms responsible for genetic variability in this group. The aim of this work is to establish the process involved with the intra/interspecific and intra/interindividual variability of diploid number, and multivalent associations in different Tityus (Archaeotityus) species, and to characterize in detail the chromosome behaviour during meiosis, considering that this behaviour possibly is associated with the maintenance of the high level of chromosome rearrangements observed in Buthidae. The mitotic and meiotic chromosomes of Tityus species will be analysed in light microscope, using classical, molecular and immunocytogenetic methodologies, aiming to determine the diploid and haploid number of chromosomes, the chromosome associations during the meiosis, distribution pattern of constitutive heterochromatin and nucleolar organizer regions, the location of ribosomal cistrons and telomeric sequences, as well as the meiotic behaviour of chromosomes regarding to synapsis, recombination, orientation and segregation, and histone modifications related to meiotic chromosome behaviour. | |