Cytogenetic markers applied to cytotaxonomy in two soybean pests: Anticarsia gemmatalis (Hübner, 1818) and Chrysodeixis includens (Walker, 1858)

Abstract

Anticarsia gemmatalis (Hü bner, 1818) and Chrysodeixis includens (Walker, 1858) are species of Lepidoptera that cause great damages in the soybean plantations of Brazil. Despite the importance they have in this regard, there are no studies on the chromosomal organization of these species and recently, A. gemmatalis, which belonged to the Noctuidae family, was allocated to the Erebidae family. Therefore, the objective of this paper was to analyze, through conventional and molecular cytogenetic markers, both species of Lepidoptera. A 2n = 62 was observed, with ZZ/ZW sex chromosome system and holokinetic chromosomes for both species. There was homogeneity in the number of 18S rDNA sites for both species. However, variations in heterochromatin distribution were observed between both species. The cytogenetic analyses enabled separation of the species, corroborating the transference of A. gemmatalis, from the family Noctuidae to the family Erebidae, suggesting new cytotaxonomic characteristics.

Transcriptional Analysis of Microsatellites in Velvetbean Caterpillar Anticarsia gemmatalis Hübner, 1818

“…Staining with propidium iodide showed 2n = 62 (60A + ZZ, ♂) for A. gemmatalis and holocentric chromosomes, the same diploid number as previously reported by Magalhães et al [2020]. Insects of the order Lepidoptera have some cytogenetic characteristics: wide variation in chromosome number, with the modal number ranging from n = 29 to n = 31 [Robinson, 1971], small and uniform holocentric chromosomes [De Vos et al, 2010;Provazníková et al, 2021], and several sex chromosome systems, being the richest group in species with female heterogamy [Hejníčková et al, 2021].…”

“…The predominance of AT repeats found with the transcriptional analysis of microsatellites was also observed cytogenetically by staining with the base-specific fluorochromes DAPI/CMA 3 , where it was possible to notice a greater prominence of DAPI-positive bands, indicating AT-rich regions. Magalhães et al [2020] did not observe DAPI-positive markings in that kind of species. This divergent result could be explained as in the current work the staining was performed in early meiotic phases (pachytene), that is, on more distended genetic material, which would facilitate the observation of these marks, in view of the cytogenetic characteristics of the species, small and numerous holocentric chromosomes, as observed in Figure 4a.…”

“…This divergent result could be explained as in the current work the staining was performed in early meiotic phases (pachytene), that is, on more distended genetic material, which would facilitate the observation of these marks, in view of the cytogenetic characteristics of the species, small and numerous holocentric chromosomes, as observed in Figure 4a. In contrast, Magalhães et al [2020] analyzed meiotic cells in metaphase, the phase of greatest chromosome condensation.…”

“…The majority of studies with A. gemmatalis are related to its behavior and relationship with synthetic and biological insecticides [Guedes et al, 2012]. There is a lack of genetic analyses and cytogenetic studies on the species, which are restricted to the location of repetitive DNAs, for example clusters of 18S rDNA [Magalhães et al, 2020]. Pezenti et al [2021], analyzing the transcriptional profile in resistant and susceptible A. gemmatalis strains bp, base pairs; SSR, simple sequence repeat; SUS, susceptible larvae fed conventional diet; SUSBt, susceptible larvae fed diet containing Bacillus thuringiensis (bt) HD73; RES, resistant larvae fed conventional diet; RESBt, resistant larvae fed diet containing Bt HD73.…”

First Cytogenetic Study Through Conventional Staining of The Ant Genus Blepharidatta Wheeler, 1915 (Hymenoptera: Formicidae: Attini)

“…= B. delabiei;Brandão et al, 2015). The analysis of mitotic chromosomes has been widely used for cytotaxonomic studies in some groups of eukaryotes (Imai, 1983;Lorite & Palomeque, 2010;Kretschmer et al, 2018;Magalhães et al, 2020). The study of karyotypes allows inferences on species differentiation, degree of kinship, evolutionary processes, and the phylogenetic position of the taxa studied (Guerra, 1988;Mariano et al, 2019).…”