Observations on spermatogenesis and nucleolar behaviour in economically important species from the Pentatomidae family (Heteroptera)

• Grant number: 07/07064-3
• Support Opportunities: Regular Research Grants
• Start date: July 01, 2008
• End date: June 30, 2010
• Field of knowledge: Biological Sciences - Morphology - Cytology and Cell Biology
• Principal Investigator: Mary Massumi Itoyama
• Grantee: Mary Massumi Itoyama
• Host Institution: Instituto de Biociências, Letras e Ciências Exatas (IBILCE). Universidade Estadual Paulista (UNESP). Campus de São José do Rio Preto. São José do Rio Preto , SP, Brazil

Abstract

In the present study, cytogenetical aspects of some phytophagous species from the Pentatomidae family will be studied. The aspects include the spermatogenesis (meiosis and spermiogenesis) and the nucleolar behaviour during these processes. We also intend to compare data from different species obtained in the present study and available in the literature to detect features indicating phylogenetic relationships among them. The techniques will involve squashing preparations stained with lacto-acetic orcein and silver nitrate, specific for chromatin and for nucleoli and nucleolar organizing regions, respectively. Cytogenetically, the Heteroptera are characterized by holocentric chromosomes (chromosomes without a specific centromere), absence of cinetocore in the meiotic cells, kinetic activity occurring exclusively in the telomeric regions of the chromosomes, and reductional division of the autosomes and equational of the sexual chromosomes in the first meiotic division. The chromosomal mechanisms of sex determination include the simple systems XY/XX (75% of the species studied) and XO/XX (15%) and multiple systems considered originated from the X chromosome fragmentation and, less frequently, from the Y chromosome (XnO/XnXn, XnY/XnXn e XYn/XX) (10%). Another system already observed in the mentioned species is the neo XY. A peculiar aspect of some Heteroptera species from the Pentatomidade family is the production of two or more spermatozoon types in a testicular lobe named harlequim. These spermatozoa differ as to the size and are considered as playing other functions, including, among others, food supplying for females. We intend, in the present study, to increase the cytogenetical and the evolutionary knowledge of some species which are important for affecting agriculture, causing representative economical losses in many regions of the world. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

VICENTE PEREIRA, LUIS LENIN; CHABOLI ALEVI, KAIO CESAR; URBANIN CASTANHOLE, MARCIA MARIA; FIGUEIREDO MOREIRA, FELIPE FERRAZ; BARBOSA, JULIANNA FREIRES; ITOYAMA, MARY MASSUMI. Cytogenetics Analysis and Testis Morphology of Aquatic Species of the Families Belostomatidae, Gelastocoridae, Gerridae, Notonectidae, and Veliidae (Heteroptera). JOURNAL OF INSECT SCIENCE, v. 15, MAR 22 2015. (07/07064-3)