5 research outputs found
Interpopulation spread of a parasitic B chromosome is unlikely through males in the grasshopper Eyprepocnemis plorans
This study was supported by grants from the Spanish Secretar铆a de Estado de Investigaci贸n,
Desarrollo e Innovaci贸n (CGL2015-70750-P), and was partially performed by FEDER funds.The near-neutral model of B chromosome evolution predicts that population invasion is quite fast. To test this prediction, in 1994, we introduced males of the grasshopper Eyprepocnemis plorans from a B-carrying population into a B-lacking population and monitored the evolution of B-chromosome frequency up to 2013. We observed fluctuating very low B frequency across years but, remarkably, the B chromosome introduced (the B2 variant) was found up to 1996 only, whereas the B1 variant was present from 1996 onwards, presumably introduced by fishermen using E. plorans males as bait. Effective introgression of genetic material from the donor population was evidenced by the presence of a satellite DNA on autosome 9 (up to 1999) and the presence of one individual in 2006 showing an ISSR marker profile being highly similar to that found in the donor population. This indicated that the males introduced by us effectively mated with resident females, but donor genes rapidly decreased in frequency after this non-recurrent migration event. Taken together, our results indicated: (i) that the non-recurrent migration event had a slight, transient genetic effect on the recipient population, which was diluted in only a few generations; and (ii) that even with recurrent migration (forced by fishermen) the B chromosome failed to increase in frequency. Bearing in mind that B chromosomes in this species drive through females only, we hypothesize that B chromosomes most likely failed invasion in both migration events because the migrating sex shows no B-drive.Spanish Secretar铆a de Estado de Investigaci贸n, Desarrollo e Innovaci贸n (CGL2015-70750-P)FEDER fund
Tandem Repeat DNA Provides Many Cytological Markers for Hybrid Zone Analysis in Two Subspecies of the Grasshopper Chorthippus parallelus
Recent advances in next generation sequencing (NGS) have greatly increased our understanding
of non-coding tandem repeat (TR) DNA. Here we show how TR DNA can be useful for
the study of hybrid zones (HZ), as it serves as a marker to identify introgression in areas where
two biological entities come in contact. We used Illumina libraries to analyse two subspecies of
the grasshopper Chorthippus parallelus, which currently form a HZ in the Pyrenees. We retrieved a
total of 152 TR sequences, and used fluorescent in situ hybridization (FISH) to map 77 families in
purebred individuals from both subspecies. Our analysis revealed 50 TR families that could serve
as markers for analysis of this HZ, using FISH. Differential TR bands were unevenly distributed
between chromosomes and subspecies. Some of these TR families yielded FISH bands in only one of
the subspecies, suggesting the amplification of these TR families after the geographic separation of
the subspecies in the Pleistocene. Our cytological analysis of two TR markers along a transect of the
Pyrenean hybrid zone showed asymmetrical introgression of one subspecies into the other, consistent
with previous findings using other markers. These results demonstrate the reliability of TR-band
markers for hybrid zone studies.Spanish Government PID2019-104952GB-I00/AEIMarie Sklodowska-Curie Individual Fellowship (European Union) 875732Junta de AndaluciaEuropean Union (Plan Andaluz de Investigacion, Desarrollo e Innovacion, PAIDI 2020)Programa Operativo Fondo Social Europeo de Andalucia 2014-2020 DOC_0110