Journal Article

Exploring the relationship between tychoparthenogenesis and inbreeding depression in the Desert Locust, Schistocerca gregaria

Jourdan‐Pineau, Hélène, Chapuis, Elodie, Little, Chelsea J., Blondin, Laurence, Chapuis, Marie‐Pierre

2017

Overview

Tychoparthenogenesis, a form of asexual reproduction in which a small proportion of unfertilized eggs can hatch spontaneously, could be an intermediate evolutionary link in the transition from sexual to parthenogenetic reproduction. The lower fitness of tychoparthenogenetic offspring could be due to either developmental constraints or to inbreeding depression in more homozygous individuals. We tested the hypothesis that in populations where inbreeding depression has been purged, tychoparthenogenesis may be less costly. To assess this hypothesis, we compared the impact of inbreeding and parthenogenetic treatments on eight life‐history traits (five measuring inbreeding depression and three measuring inbreeding avoidance) in four laboratory populations of the desert locust, Schistocerca gregaria, with contrasted demographic histories. Overall, we found no clear relationship between the population history (illustrated by the levels of genetic diversity or inbreeding) and inbreeding depression, or between inbreeding depression and parthenogenetic capacity. First, there was a general lack of inbreeding depression in every population, except in two populations for two traits. This pattern could not be explained by the purging of inbreeding load in the studied populations. Second, we observed large differences between populations in their capacity to reproduce through tychoparthenogenesis. Only the oldest laboratory population successfully produced parthenogenetic offspring. However, the level of inbreeding depression did not explain the differences in parthenogenetic success between all studied populations. Differences in development constraints may arise driven by random and selective processes between populations. The existence of parthenogenesis is still a question in evolution because of the advantages of sexual reproduction. Species, which exhibit occasional or accidental parthenogenesis (i.e., tychoparthenogenesis), such as the desert locust (Schistocerca gregaria), provide the opportunity to directly compare sexual and parthenogenetic reproduction. However, we found no clear relationship between the level of inbreeding, inbreeding depression, and parthenogenetic capacity suggesting that others selective or random processes may have to be taken into account.

• Publisher: John Wiley & Sons, Inc,Wiley Open Access,John Wiley and Sons Inc
• Subject: Asexual reproduction / Avoidance / Demographics / desert locust / Eggs / Environmental Sciences / Evolution / Fitness / Genetic diversity / Hypotheses / Inbreeding / Inbreeding depression / Laboratories / Life history / Offspring / Original Research / parthenogenesis / Population studies / Populations / Purging / Reproduction (biology) / Reproductive fitness / Schistocerca gregaria