Sexual attractiveness and reproductive performance in ageing females of a coccoid insect

Female age strongly influences reproductive success in various animals. Males are, therefore, expected to show preferential responses to sexual signals released from females of ages suitable for reproduction. Here, however, we report an unexpected and contradictory effect of ageing on sexual attractiveness and reproductive performance in a coccoid insect: the pheromone-based attractiveness of females increased with ageing, though their reproductive performance was in rapid decline. Surprisingly, senescent females continued releasing relatively high amounts of pheromone and maintained their sexual attractiveness, even at ages when they had almost completely lost fertility, with reduced densities of endosymbionts to support their physiology. Our dataset suggests a potential sexual conflict within a pheromone communication system, where females benefit at males' expense through deceptive signals of fertility.

Download Full-text

Sex Pheromone Communication System in Hawk Moths

Insect Sex Pheromone Research and Beyond - Entomology Monographs ◽

10.1007/978-981-15-3082-1_2 ◽

2020 ◽

pp. 19-33

Author(s):

Takuya Uehara ◽

Hiroshi Honda

Keyword(s):

Sex Pheromone ◽

Communication System ◽

Pheromone Communication ◽

Pheromone Communication System

Download Full-text

Two-step activation of meiosis by the mat1 locus in Schizosaccharomyces pombe.

Molecular and Cellular Biology ◽

10.1128/mcb.15.9.4964 ◽

1995 ◽

Vol 15 (9) ◽

pp. 4964-4970 ◽

Cited By ~ 63

Author(s):

M Willer ◽

L Hoffmann ◽

U Styrkársdóttir ◽

R Egel ◽

J Davey ◽

...

Keyword(s):

Schizosaccharomyces Pombe ◽

Fission Yeast ◽

Communication System ◽

Ectopic Expression ◽

Cell Types ◽

M Cells ◽

Haploid Cell ◽

Pheromone Communication ◽

Mating Pheromones ◽

Pheromone Communication System

The mat1 locus is a key regulator of both conjugation and meiosis in the fission yeast Schizosaccharomyces pombe. Two alternative DNA segments of this locus, mat1-P and mat1-M, specify the haploid cell types (Plus and Minus). Each segment includes two genes: mat1-P includes mat1-Pc and mat1-Pm, while mat1-M includes mat1-Mc and mat1-Mm. The mat1-Pc and mat1-Mc genes are responsible for establishing the pheromone communication system that mediates conjugation between P and M cells, while all four mat1 genes are required for meiosis in diploid P/M cells. Our understanding of the initiation of meiosis is based largely on indirect observations, and a more precise investigation of these events was required to define the interaction between the mat1 genes. Here we resolve this issue using synthetic pheromones and P/M strains with mutations in either mat1-Pc or mat1-Mc. Our results suggest a model in which the mat1 locus plays two roles in controlling meiosis. In the first instance, the mat1-Pc and mat1-Mc functions are required to produce the mating pheromones and receptors that allow the generation of a pheromone signal. This signal is required to induce the expression of mat1-Pm and mat1-Mm. This appears to be the major pheromone-dependent step in controlling meiosis since ectopic expression of these genes allows meiosis in the absence of mat1-Pc and mat1-Mc. The mat1-Pm and mat1-Mm products complete the initiation of meiosis by activating transcription of the mei3 gene.

Download Full-text

Familiarity between mates improves few aspects of reproductive performance in house sparrows

Behaviour ◽

10.1163/156853908783402867 ◽

2008 ◽

Vol 145 (3) ◽

pp. 365-376 ◽

Cited By ~ 11

Author(s):

David Westneat ◽

Margret Hatch

Keyword(s):

Reproductive Success ◽

Reproductive Performance ◽

Older Individuals ◽

House Sparrows ◽

Female Age

AbstractMany hypotheses have been proposed to account for the increased reproductive success with age documented in most birds. One, the mate familiarity hypothesis, suggests that older individuals are likely to have partners with whom they have bred before, which may enhance reproductive success. We found that pairs of house sparrows that bred together previously fledged more young than pairs that were newly formed. This was primarily due to newly-formed pairs with at least one yearling having fewer nesting attempts than continuing pairs. We also examined the possibility that continuing pairs were better coordinated in parental duties, but found no evidence for this in terms of amount of overlap at the nestbox or amount of time nestlings were unattended. Our results suggest the higher success of continuing pairs may be a matter of female age and quality and not due to benefits accrued by coordination with their mate.

Download Full-text