Two new species of the bathyal holothurian genus Pannychia (Elasipodida, Laetmogonidae) from Japanese waters.

Sea cucumbers are one of the most common large animals in the deep-sea benthic communities, and those of the genus Pannychia are particularly abundant in the bathyal North Pacific Ocean. In Japanese waters, three species of Pannychia have been reported, mainly from the northern and eastern parts of the country. Here, we describe two new species from the western part of Japan. These two new species were placed in Pannychia by the presence of dorsal papillae on the ventrolateral radii and the presence of large wheel ossicles with rim teeth. They are distinguished from all other nominal species of Pannychia on the basis of the morphological characteristics of their body wheel ossicles. Pannychia nagasakimaruae sp. nov. has a unique ossicle composition in its dorsal and ventral body walls: four forms of wheel ossicles. Pannychia rinkaimaruae sp. nov. differs from other congeners in its small wheel ossicles in the dorsal and ventral body walls, which have conical rim teeth. We barcoded partial COI gene sequences from holotypes and paratypes of two new Japanese species. Our molecular phylogenetic analysis showed that these two new morphologically recognized Japanese species form distinct clades separated from other Pacific Pannychia species, so that the two new Japanese species were also supported by genetic results. In addition, we describe and visualize the poorly calcified calcareous rings of the two new species using X-ray µCT system, a useful method for observing such structures, which are important structures in holothurian anatomy.

Extra-pair paternity in the wood-feeding cockroach Cryptocercus punctulatus Scudder: Social but not genetic monogamy.

Subsocial Cryptocercus cockroaches are the sister group to termites and considered to be socially monogamous. Because genetic monogamy is a suggested requirement for evolution of cooperative breeding/eusociality, particularly in hymenopterans, clarification of the mating biology of Cryptocercus would help illuminate evolutionary trends in eusocial insects. To investigate possible extra-pair paternity in C. punctulatus, microsatellite markers were used to analyse offspring parentage, the stored sperm in females and results of experimental manipulation of sperm competition. Extra-pair paternity was common in field-collected families, but a lack of maternal alleles in several nymphs suggests sampling error or adoption. Isolating prereproductive pairs and assaying subsequently produced nymphs confirmed that nymphs lacked alleles from the pair male in 40% of families, with extra-pair male(s) siring 27%-77% of nymphs. Sperm of extra-pair males was detected in the spermatheca of 51% of paired prereproductive females. Mate switching and surgical manipulation of male mating ability indicated a tendency towards last male sperm precedence. Overall, the results demonstrate that about half of young females are serially monogamous during their maturational year, but bond, overwinter and produce their only set of offspring in company of the last mated male (=pair male). Repeated mating by the pair male increases the number of nymphs sired, but because many females use stored sperm of previous copulatory partners to fertilize eggs, pair males extend parental care to unrelated nymphs. The results suggest that genetic monogamy either developed in the termite ancestor after splitting from the Cryptocercus lineage, or that genetic monogamy may not be a strict prerequisite for the evolution of termite eusociality.

Two new deep-sea species of the genus Henricia (Asteroidea: Spinulosida: Echinasteridae) from Japanese waters.

Two new deep-sea Henricia species, Henricia margarethae n. sp. and Henricia fragilis n. sp. are described from Sagami Bay and the Ogasawara Islands in Japan. The two new species show an affinity with eight congeners in having multiple furrow spines and abactinal papular areas which are larger than surrounding plates. The two species described herein are characterized by the arrangement of abactinal pseudopaxillae, the arrangement of abactinal papulae, the shape and arrangement of abactinal spines, the length of intermarginal and ventrolateral series, and the armament of superomarginal, inferomarginal, and adambulacral plates.

Fbx8 makes Arf6 refractory to function via ubiquitination.

The small GTP-binding protein Arf6 regulates membrane remodeling at cell peripheries and plays crucial roles in higher orders of cellular functions including tumor invasion. Here we show that Fbx8, an F-box protein bearing the Sec7 domain, mediates ubiquitination of Arf6. This ubiquitination did not appear to be linked to immediate proteasomal degradation of Arf6, whereas Fbx8 knockdown caused hyperactivation of Arf6. Expression of Fbx8 protein was substantially lost in several breast tumor cell lines, in which Arf6 activity is pivotal for their invasion. Forced expression of Fbx8 in these cells suppressed their Arf6 activities and invasive activities, in which the F-box and Sec7 domains of Fbx8 are required. Together with the possible mechanism as to how Fbx8-mediated ubiquitination interferes with the functions of Arf6, we propose that Fbx8 provides a novel suppressive control of Arf6 activity through noncanonical ubiquitination. Our results indicate that dysfunction of Fbx8 expression may contribute to the invasiveness of some breast cancer cells.