Yoshikazu Ando

Multiple Paternity within Field-Collected Egg Cases of the Praying Mantid Tenodera aridifolia

ABSTRACT We developed microsatellite loci to examine the occurrence of multiple paternity in the praying mantid Tenodera aridifolia Stoll, as inferred from the genotypes of the progeny within field-collected oothecae (egg cases). The microsatellite locus MTA, developed from field-caught mantids, was found to have three alleles (A, B, and C) among >600 hatchlings from 18 oothecae from two locations in Japan. Of the 18 oothecae, two show clear evidence of multiple sires, two show equivocal evidence of multiple sires, and the remaining 14 do not show evidence of multiple sires. Thirteen of the latter 14 oothecae are exclusively homozygous, with all progeny being of the same genotype (BB). Although the exclusively homozygous oothecae suggest a high incidence of monogamy in these field populations, we caution that we probably underestimated the incidence of multiple paternity, given our use of one locus with three alleles. This study is the first genetic investigation of field-collected progeny of a sexually cannibalistic species, as well as the first demonstration of multiple paternity in nature for a sexually cannibalistic species.

Molecular cytogenetic characterization and chromosomal distribution of the satellite DNA in the genome of Oxya hyla intricata (Orthoptera: Catantopidae)

The genomic DNA of the grasshopper (Oxya hyla intricata) was subjected to electrophoresis after digestion with HaeIII, and the result showed two bands of highly repetitive DNA, approximately 200 and 400 bp in length. The 200-bp HaeIII-digested fragment was cloned and characterized by sequencing and fluorescence in situ hybridization (FISH). The results showed the presence of two distinct satellite DNA (stDNA) families: one consisting of a 169-bp repeated element having an A+T content of 60.9% and the other consisting of a 204-bp repeated element having an A+T content of 53.9%. No significant homology between the two stDNA families was observed. FISH showed that the chromosomal locations of these families are different from each other. The 169-bp element was located in the C-band-positive regions of the short arms of most of the chromosomes, whereas the 204-bp element was located in the centromeric regions of three chromosome pairs. These results imply that the origins of these two DNA families are different. The results of zoo-blot hybridization to the genomic DNA from four Oxya species, O. hyla intricata, O. japonica japonica, O. chinensis formosana, and O. yezoensis, suggest that the two stDNA families found in the present study are species-specific for O. hyla intricata.

Egg development patterns in diapausing and non-diapausing species of Ruspolia

The egg development of the African bushcricket Ruspolia differens is shown to be direct, without any delay, and to be highly synchronised. It is also strongly temperature dependent and closely fits the thermal summation equation Days = (T°C‐14.8)/252, even if incubation temperatures (T) are changed during the course of development. In contrast egg development in the closely related Southern European Ruspolia nitidula is subject to a form of diapause after anatrepsis but its other developmental characteristics are very similar to R. differens. Diapause in R. nitidula may disappear in time without change of temperature and is thus unlike any diapause reported for other Tettigoniidae. Chilling diapausing eggs progressively synchronises and advances hatching, the full effect being achieved in 8 weeks at 8 °C. Development in post‐diapause eggs is independent of diapause treatment.