Local gamete competition explains sex allocation and fertilization strategies in the sea.

Appendix B from J . M . Henshaw et al . , “ Local Gamete Competition Explains Sex Allocation

In the robustness analysis, we generated parameter values randomly for each trial. Here we present the range of values from which each parameter was chosen (table B1). We also justify our choice of ranges for scaling exponents. These exponents determine the allometric relationships between body size, population density, and pumping ability and between egg size and fertilization efficiency. Last...

LETTERS TO NATURE Effects of gamete traits on fertilization in the sea and the evolution of sexual dimorphism

Gamete compatibility and sperm competition affect paternity and hybridization between sympatric Asterias sea stars.

Gamete interactions may strongly influence speciation and hybridization in sympatric broadcast-spawning marine invertebrates. We examined the role of gamete compatibility in species integrity using cross-fertilization studies between sympatric Asterias sea stars from a secondary contact zone in the northwest Atlantic. In crosses between single males and single females, gametes of both species w...

Selection for high gamete encounter rates explains the success of male and female mating types.

Sexual reproduction occurs in many small eukaryotes by fusion of similar gametes (isogamy). In the absence of distinguishable sperm and eggs, male and female mating types are missing. However, species with distinct males and females have so prospered that almost all familiar plants and animals have these mating types. Why has sexual reproduction involving sperm and eggs been so successful? An a...

Sperm-induced local [Ca2+]i rise separated from the Ca2+ wave in sea urchin eggs in the presence of a gamete fusion inhibitor, jaspisin .

An increase in intracellular Ca2+ concentration ([Ca2+]i) at a focal plane was recorded simultaneously with sperm-egg binding and membrane current upon insemination of sea urchin Hemicentrotus pulcherrimus eggs. No change in current and [Ca2+]i occurred in the presence of jaspisin, a novel substance that inhibits metallo-endoproteinase and sperm-egg membrane fusion (S. Ikegami, H. Kobayashi, Y....