Variation in genome size and karyotype among closely related aphid parasitoids (Hymenoptera, Aphelinidae)

By

Gokhman, V. E. (Vladimir Evseevich)
Kuhn, Kristen L
Woolley, James Braden
Hopper, Keith R.

Type

Article

Date of Publication

2017-2-23

Original Publication

Comparative cytogenetics : international journal of plant & animal cytogenetics, karyosystematics and molecular systematics

Volume

11

Series / Issue

Issue: 1

Pages

97--117

Subjects

Aphelinidae , Aphelinus , flow cytometry , genome size , karyotype , parasitoid

Contributed by

Pensoft Publishers

Language

English

Published by

St. Petersburg, Russia [Published] with technical support of Zoological Institute RAS [2007]-

Identifiers

DOI: https://doi.org/10.3897/CompCytogen.v11i1.10872

 

Abstract

Genome sizes were measured and determined for the karyotypes of nine species of aphid parasitoids in the genusAphelinusDalman,1820. Large differences in genome size and karyotype were found betweenAphelinusspecies, which is surprising given the similarity in their morphology and life history. Genome sizes estimated from flow cytometry were larger for species in theAphelinusmali(Haldeman, 1851) complex than those for the species in theAphelinusdaucicolaKurdjumov, 1913 andAphelinusvaripes(Förster,1841) complexes. Haploid karyotypes of theAphelinusdaucicolaandAphelinusmalicomplexes comprised five metacentric chromosomes of similar size, whereas those of theAphelinusvaripescomplex had four chromosomes, including a larger and a smaller metacentric chromosome and two small acrocentric chromosomes or a large metacentric and three smaller acrocentric chromosomes. Total lengths of female haploid chromosome sets correlated with genome sizes estimated from flow cytometry. Phylogenetic analysis of karyotypic variation revealed a chromosomal fusion together with pericentric inversions in the common ancestor of theAphelinusvaripescomplex and further pericentric inversions in the clade comprisingAphelinuskurdjumoviMercet, 1930 andAphelinushordeiKurdjumov, 1913. Fluorescencein situhybridization with a 28S ribosomal DNA probe revealed a single site on chromosomes of the haploid karyotype ofAphelinuscoreaeHopper & Woolley, 2012. The differences in genome size and total chromosome length between species complexes matched the phylogenetic divergence between them.