ABSTRACT
Mitochondrial genomes have provided significant insights into the evolution of several insects. A typical mitogenome contains 37 genes, and variations in gene order can indicate evolutionary relationships between species. In this study, we have assembled the first complete mitogenomes of Endecous chape and E. onthophagus and analyzed the phylogenetic implications for the Gryllidea infraorder. We performed DNA extractions and genome sequencing for both Endecous species. Subsequently, we searched for raw data in the Sequence Read Archive (SRA) in NCBI. Using the SRA data, we assembled the partial mitogenome of Dianemobius nigrofasciatus and annotated the protein-coding genes (PCGs) for nine species. Phylogenomic relationships were reconstructed using Maximum Likelihood (ML) and Bayesian Inference (BI), utilizing the PCGs from 49 Gryllidea species. The mitogenome lengths of E. chape and E. onthophagus are 16,266 bp and 16,023 bp, respectively, while D. nigrofasciatus has a length of 15,359 bp. Our results indicate that species within the infraorder exhibit four types of gene order arrangements that align with their phylogenetic relationships. Both phylogenomic trees displayed strong support, and the ML corroborated with the literature. Gryllidea species have significantly contributed to various fields, and studying their mitogenomes can provide valuable insights into this infraorder evolution.
ABSTRACT
Sperberacris, a new Neotropical genus of Amblytropidiini. Sperberacris muriciensis n. sp. (type species) from the municipality of Murici, State of Alagoas, Brazil is described. The new genus differs from other tribe congenera by the epiproct suboval, furculae divided into four long sclerotized lobes, cerci curved inward, apex truncated and sclerotized at the tip and convex bridge of the epiphallus with two large black sclerotized spots. The new species presents a diploid number of 2n = 23, X0â/24, XXâ, and the karyotype is made up of telo/acrocentric chromosomes, with one dot-like B chromosome occurring in some nuclei. Morphological descriptions are provided along with illustrations emphasizing the most significant diagnostic features of external morphology and male genitalia. Information on type specimens, material examined, and distribution provided.
Subject(s)
Grasshoppers , Orthoptera , Male , Animals , Brazil , Diploidy , Genitalia, Male , Karyotype , Animal DistributionABSTRACT
Karyotypes in the worldwide subfamily Oecanthinae show variations in diploid number, chromosome morphology, and sex-chromosome system. This study described the chromosome set and phylogenetic relationships of four Neotropical species, Oecanthus lineolatus, O. valensis, O. pallidus, and O. pictus. We used classical cytogenetics and Bayesian Inference for phylogenetic reconstruction, using the mitochondrial genes COI, 12S rRNA, and 16S rRNA; and analyzed the phylogenetic patterns of changes in chromosome numbers, using ChromEvol. We observed differences in chromosome number among species and two different sex-chromosome systems. Oecanthus pictus showed 2n = 21, X0â/22, XXâ; O. lineolatus, 2n = 20, XYâ/XXâ; and O. valensis and O. pallidus, 2n = 18, XYâ/XXâ. The karyotype of Oecanthus was asymmetric, one group with large chromosomes and variation in heterochromatin distribution, and another with small acrocentric chromosomes. The phylogenetic tree recovered two main groups: one with the Palearctic species and another with species from different bioregions, but with low posterior probability. The Neotropical species grouped separately, O. valensis and O. pictus with Nearctic and Ethiopian species, and O. pallidus and O. lineolatus in another, well-supported clade. Together, the phylogenic and chromosome data suggest descending dysploidy events during the evolution of the group.
