What Use is an Infertile Sperm? A Comparative Study of Sperm-Heteromorphic Drosophila

  title={What Use is an Infertile Sperm? A Comparative Study of Sperm-Heteromorphic Drosophila},
  author={Luke Holman and Robert P. Freckleton and Rhonda R. Snook},
  booktitle={Evolution; international journal of organic evolution},
Abstract Sperm size and number are important determinants of male reproductive success. The genus Drosophila exhibits a remarkable diversity of sperm production strategies, including the production of multiple sperm morphs by individual males, a phenomenon called sperm heteromorphism. Sperm-heteromorphic Drosophila species in the obscura group produce large numbers of infertile “parasperm” in addition to fertile eusperm. Parasperm have been hypothesized to perform a number of roles in place of… 

Identification of a novel sperm class and its role in fertilization in Drosophila

Evidence of males depositing two morphologically distinct types of parasperm into the female reproductive tract in Drosophila pseudoobscura is documented, showing how both sperm competition and cryptic female choice may be acting in conjunction to influence the evolution of ejaculate composition.

Repeated evidence that the accelerated evolution of sperm is associated with their fertilization function

This study provides direct evidence that sperm length evolves more rapidly in fertile sperm, probably because of their functional role in securing male fertility and in response to selection imposed by female reproductive organs.

Integrated and independent evolution of heteromorphic sperm types

The results suggest that sperm, despite sharing a common developmental process, can become developmentally and functionally non-integrated, evolving into separate modules with the potential for rapid and independent responses to selection.

Experimental Manipulation of Sexual Selection Promotes Greater Male Mating Capacity but does not Alter Sperm Investment

It is found that testis mass may not be a frequent target of postcopulatory sexual selection and, even when it is, the resulting changes do not always improve fitness.

Female reproductive tract form drives the evolution of complex sperm morphology

Results of Bayesian analyses suggest that the loss of sperm conjugation is driven by elongation of the female reproductive tract, and underscore the importance of postcopulatory sexual selection as an agent of diversification.

Sperm wars and the evolution of male fertility.

It is argued that future research must consider sperm and seminal fluid components of the ejaculate as a functional unity, and that research at the genomic level will identify the genes that ultimately control male fertility.


It is found that sperm number may be limited by low heritability and evolvability whereas sperm quality has moderate VA and CVA but does not evolve, and the female reproductive tract, suggested to drive the evolution of sperm, did not respond to experimental sexual selection even though there was sufficient genetic variation.

Sperm metabolic rate predicts female mating frequency across Drosophila species

The results demonstrate the importance of sperm metabolism in sexual selection by measuring sperm metabolism across 13 Drosophila species and comparing these measures to published data on female mating rate and on sperm length.



The risk of sperm competition and the evolution of sperm heteromorphism

Oviposition per se is probably more important than sperm in determining female receptivity and that sperm heteromorphism may play a marginal, if any, role in affecting female remating, according to research in Drosophila obscura.

Mating system evolution in sperm-heteromorphic Drosophila.

Spermicide, cryptic female choice and the evolution of sperm form and function

Two female‐centred hypotheses for the evolution and maintenance of sperm heteromorphism are examined, using game theoretical models to establish that parasperm may function to protect eusperm from female‐generated spermicide, and to elucidate the predictions of this idea.

Coevolution of sperm and female reproductive tract morphology in stalk–eyed flies

Morphological coevolution between sperm and female reproductive tracts is consistent with a history of female–mediated selection on sperm length and two lines of evidence indicate that ‘short sperm’, which are probably incapable of fertilization, coevolve with spermathecae.

The evolution of sperm length in moths

  • E. H. MorrowM. Gage
  • Biology
    Proceedings of the Royal Society of London. Series B: Biological Sciences
  • 2000
a comparative study examining how sperm lengths are associated with male and female reproductive characters across moths found a positive relationship between the residual testis volume and spermathecal volume, suggesting coevolution between male investment in sperMatogenesis and the extent of the female sperm storage capacity.

Sperm length influences fertilization success during sperm competition in the snail Viviparus ater

The size of oligopyrene sperm was the best predictor of fertilization success, with males having the longer sperm siring the highest proportion of offspring, and a positive shell size and sperm concentration effect on paternity suggests polyandry is beneficial for female snails.

The long and short of sperm polymorphisms in insects

Evidence on the distribution and development of sperm heteromorphisms among insects in light of competing hypotheses for the evolutionary origin, maintenance, and function of a non‐fertilizing class of sperm is critically examined.


The macroevolutionary pattern of organ dysfunction and morphological divergence suggests that ancestrally both kinds of organs stored sperm, and data indicate that the seminal receptacle is the primary sperm‐storage organ in Drosophila.

Functional nonequivalence of sperm in Drosophila pseudoobscura.

It is found that two size classes of sperm are produced and transferred to females in approximately equal numbers by the male; only long sperm persist in significant numbers in female sperm storage organs, falsifying those hypotheses in which all sperm types are assumed to be functionally equivalent (fertilize eggs).

Sperm-Female Coevolution in Drosophila

Using populations of Drosophila melanogaster selected for divergent sperm length or female sperm-storage organ length, experimentally show that male fertilization success is determined by an interaction between sperm and female morphology.