Nuclear Ribosomal Internal Transcribed Spacer 1 (ITS1) variation in Lady Bird Beetles (Coccinellidae)

Abstract

The seventeen taxa of the family Coccinellidae were analyzed by sequencing the Internal Transcribed Spacer 1 region followed by analyzing the presence of significantly simple motifs (SSMs), to investigate the presence of functionally important areas in the gene if any and to find phylogenetic inference of the ITSI region between sequenced species. Length comparisons among the ITS 1 region indicated the absence of intraspecific variability. Further, length differences observed were among Adalia bipunctata showing a 3 bp maximum size difference and Psyllobora vigintiduopunctata with 1 bp size difference. The base composition showed highly similar values of A, T, G and C. Except Harmonia axyridis, Phyllobora vigintiduopunctata, Chilocorus renipustulatu, Lemnia duvauceli all other species showed significant number of simple repetitions. Adalia bipunctata showed the highest simple repetition with the RSF value of 1.4440. Thirteen ladybird beetles had higher SSM regions. Adalia bipunctata, Adalia decempunctata, Exochomus quadripustulatus shows high accumulation of AT repeats in 5 prime end flanking region and GC repeats in 3 prime end flanking region. Amida nigropectoralis, Amida quingquefasiata, Menochilus sexmaculata, Phaenochilus mesternalis, Coccidula rufa, Platynaspis luterubra shows a higher concentration of GC repeats towards the 3 prime end flanking regions. Phylogenetic analysis revealed that the tribe Psylloborini of the subfamily Coccinellidae was monophyletic. The members of the Subfamily Chilocorinae first associate with the tribes of subfamily Coccinellidae and then relate with the tribe Scymnini. Exochomus quadripustulatus which shows the highest length variably showed a relationship with Phaenochilus mesternalis 77 bootstrap and 84 posterior probabilities.