Parallel changes in mate-attracting calls and female preferences in autotriploid tree frogs

Abstract

For polyploid species to persist, they must be reproductively isolated from their diploid parental species, which coexist at the same time and place at least initially. In a complex of biparentally reproducing tetraploid and diploid tree frogs in North America, selective phonotaxis-mediated by differences in the pulserepetition (pulse rate) of their mate-attracting vocalizations-ensures assortative mating. We show that artificially produced autotriploid females of the diploid species (Hyla chrysoscelis) show a shift in pulserate preference in the direction of the pulse rate produced by males of the tetraploid species (Hyla versicolor). The estimated preference function is centred near the mean pulse rate of the calls of artificially produced male autotriploids. Such a parallel shift, which is caused by polyploidy per se and whose magnitude is expected to be greater in autotetraploids, may have facilitated sympatric speciation by promoting reproductive isolation of the initially formed polyploids from their diploid parental forms. This process also helps to explain why tetraploid lineages with different origins have similar advertisement calls and freely interbreed.

The Influence of Genome and Cell Size on Brain Morphology in Amphibians

“…Taking this into account, the behavioral preference of females for different pulse repetition rates in di-, tri-, and tetraploid specimen of the Hyla chrysoscelis complex might be a consequence of different genome sizes, which affect cell dimensions (Keller and Gerhardt 2001;Tucker and Gerhardt 2012). Moreover, electrophysiological recordings in the torus of B. bombina (11.38 pg) with large neurons and R. temporaria (4.26 pg) with smaller neurons indicate that neurons in B. bombina do not synchronize to high stimulus pulse repetition rates as do neurons in R. temporaria (Walkowiak 1980).…”

Geographic variation in hybridization across a reinforcement contact zone of chorus frogs (Pseudacris)

“…Thus, the genetic architecture underlying pulse rate and pulse number is expected to be complex, potentially involving many genes. What is known about the genomic basis of frog calls is that gene dosage affects frog signals-ploidy level is correlated with trait values (Guignard, Büchi, Gétaz, Betto-Colliard, & Stöck, 2012;Hoffman & Reyer, 2013;Keller & Gerhardt, 2001;Mable & Bogart, 1991;Tucker & Gerhardt, 2012). More is known about the genetic architecture of acoustic signals in insects-for example, in crickets several quantitative trait loci have been identified that control pulse rate (Ellison, Wiley, & Shaw, 2011;Shaw & Lesnick, 2009;Shaw, Parsons, & Lesnick, 2007).…”

Progesterone and prostaglandin F2α induce species-typical female preferences for male sexual displays in Cope's gray treefrog (Hyla chrysoscelis)

“…This finding is important in light of earlier work on the roles of hormones in the mate choice behaviors of female frogs [6, 31, 46, 47]. Several previous studies have shown that hormone administration can induce sexual proceptivity in female frogs [13, 32, 33, 42-44, 50, 63, 64]. Only three previous studies of only two species ( H. versicolor and Physalaemus pustulosus ) have shown that hormone administration can induce species-typical patterns of sexual selectivity in the context of intraspecific mate choice [13, 32, 33].…”