Chromosomal identification of cryptic species sharing their DNA barcodes: Polyommatus (Agrodiaetus) antidolus and P. (A.) morgani in Iran (Lepidoptera, Lycaenidae).

Vladimir A Lukhtanov,Nazar A Shapoval

doi:10.3897/compcytogen.v11i4.20876

Abstract

DNA barcoding has been suggested as a universal tool for molecular species identification; however, it cannot be applied in cases when morphologically similar species share their DNA barcodes due to the common ancestry or mitochondrial introgression. Here we analyze the karyotype of Polyommatus (Agrodiaetus) morgani (Le Cerf, 1909) from the region of its type locality in the southern Zagros Mountains in Iran, provide first chromosomal evidence for P. (A.) antidolus (Rebel, 1901) in Iran and demonstrate that these two species can be easily identified through analysis of their karyotypes whereas they share their mitochondrial barcodes.

Highlights

Cryptic species, morphologically indistinguishable or highly similar biological entities, represent a substantial portion of plant and animal diversity, and the search for these species is important for taxonomic, ecological and evolutionary studies (Beheregaray and Caccone 2007, Pfenninger and Schwenk 2007, Dincă et al 2013, Vodă et al 2015)
Cryptic species can usually be identified through analysis of molecular markers (Vodă et al 2015), e.g. through analysis of the so-called DNA barcodes, short genetic sequences from a standard part of the genome (Hebert et al 2003)
The use of the standard DNA barcodes such as short fragments of the mitochondrial gene COI and the non-coding nuclear sequence, internal transcribed spacer 2 (ITS2), is sometimes insufficient to distinguish between evolutionarily young sister species, either because they can be weakly differentiated regarding these markers or because they are too polymorphic (Avise 2000, Lukhtanov et al 2015a, b, 2016)

Summary

Introduction

Morphologically indistinguishable or highly similar biological entities, represent a substantial portion of plant and animal diversity, and the search for these species is important for taxonomic, ecological and evolutionary studies (Beheregaray and Caccone 2007, Pfenninger and Schwenk 2007, Dincă et al 2013, Vodă et al 2015). (A.) morgani (Le Cerf, 1909), a complex of three closely related allopatric species distributed in east Turkey as well as in west and central Iran (Fig. 1) (Eckweiler and Bozano 2016), represent a good example of such situation. Despite morphological similarity (Fig. 2) and identity of COI barcodes in the majority of the studied populations (see Table 2 and sequences published in Wiemers 2003, Wiemers and Fiedler 2007, Kandul et al 2004, 2007, Lukhtanov et al 2015b and see Lukhtanov et al 2015b for the exceptions), they can be identified by their chromosome numbers.

Results

Conclusion