Comparative cytogenetic analysis in Pholcidae spiders (Araneomorphae, Haplogynae)

• Grant number: 12/10679-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2012
• End date: December 31, 2013
• Field of knowledge: Biological Sciences - Zoology - Morphology of Recent Groups
• Principal Investigator: Marielle Cristina Schneider
• Grantee: Rafael Lucena Lomazi
• Host Institution: Instituto de Ciências Ambientais, Químicas e Farmacêuticas (ICAQF). Universidade Federal de São Paulo (UNIFESP). Campus Diadema. Diadema , SP, Brazil

Abstract

Pholcidae spiders are morphologically characterized by their small size of cephalothorax and abdomen in relation to the legs, which are extremely long and can reach up to twenty times the size of the body. Within the group of Haplogynae spiders, this family is the largest, with 1.241 species distributed in five subfamilies: (Ninetinae (Arteminae + Modisiminae) (Pholcinae + Smeringopinae)). Cytogenetically, only 19 species of Pholcidae have been characterized, which showed diploid numbers ranging from 2nB=15 to 2nB=32 and sex chromosome systems of the X0, XY, X1X20 and X1X2Y types. This diversity of sex chromosome systems observed in Pholcidae is the biggest already found in Haplogynae spiders. Furthermore, species with similar type of sex chromosome system can differ in relation to the chromosome association during meiosis; this data indicates that these chromosomes could be in distinct stages of evolution. Most cytogenetic studies in representatives of this family was accomplished with a standard chromosome staining; only four species were examined regarding to the distribution of the constitutive heterochromatin or nucleolar organizer regions. The identification of these chromosomes regions certainly will provide data about the genome organization and karyotype evolution of Pholcidae. In this work, pholcid spiders of the Brazilian fauna will be characterized, aiming to add data regarding to the cytogenetic knowledge of the group and contribute for the understanding of the mechanisms of chromosomal evolution. The analysis will be performed in species of four distinct subfamilies, by conventional and differential staining. (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)

LOMAZI, RAFAEL LUCENA; ARAUJO, DOUGLAS; CARVALHO, LEONARDO SOUSA; SCHNEIDER, MARIELLE CRISTINA. Small pholcids (Araneae: Synspermiata) with big surprises: the lowest diploid number in spiders with monocentric chromosomes. JOURNAL OF ARACHNOLOGY, v. 46, n. 1, p. 45-49, APR 2018. (11/21643-1, 12/10679-8)