Weakly electric fishes emit electric organ discharges (EODs) from their tail electric organs and sense feedback signals from their EODs by electroreceptors in the skin. The electric sense is utilized for various behaviors, including electrolocation, electrocommunication, and the Jamming avoidance response (JAR). For each behavior, various types of sensory Information are embedded in the transient electrical signals produced by the fish. These temporal signals are sampled, encoded, and further processed by peripheral and central neurons specialized for time coding. There are time codes for the sex or species Identities of other fish or the resistance and capacitance of objects. In the central nervous system, specialized neural elements exist for decoding time codes for different behavioral functions. Comparative studies allow phylogenetic comparison of time-coding neural systems among weakly electric fishes.

S-100 proteins are calcium-activated signaling proteins that interact with other proteins to modulate biological functions such as cell migration, growth, proliferation, differentiation, apoptosis, contraction, and the inflammatory response. Although S-100 proteins are expressed in neuronal and non-neuronal tissues, their localization in the uropygial gland was not known. This study concerns the immunohistochemical detection of localization of S-100α, S-100β, and wbS-100 in the chicken uropygial gland during development from days 1–150 days post-hatching. In 1-day-old chicks, the nuclei and cytoplasm of cells in the luminal epithelium and the tubules of the gland stained positively for S-100α, S-100β, and wbS-100. Seven days after hatching, immunoreactivity for S-100α, S-100β, and wbS-100 was detected in the nucleus and cytoplasm of cells in the germinative and intermediate layers of the central zone, but was found only in the germinative layer of the peripheral zone. In addition, in cells of the degenerative and secretory layers of both the central and peripheral zones, S-100α, S-100β, and wbS-100 were present in the plasma membrane. In uropygial glands studied from days 7–150 post-hatching, the number of immunopositive cells in the central zone increased with the advance of age and glandular growth. The results indicated that the chicken uropygial gland contains both αβ and ββ dimers. Although the biological significance of the expression of wbS-100 and its subunits in the uropygial gland remains unknown, these notable calcium-binding proteins may be associated with the processes of gland-cell differentiation and apoptosis, and the antimicrobial properties of preen wax or lipids.

We studied the phylogenetic relationships among populations of Rana sauteri using partial sequences of the mitochondrial cytochrome b gene from 244 samples from 29 localities in Taiwan. We detected 77 haplotypes among these sequences. The phylogenetic trees contained five distinct lineages: the northern (NL), eastern (EL), southern hill (SHL), northern mountain (NML), and southern mountain (SML) lineages, defined by geographical distribution. The lineage phylogeny did not support the two-species hypothesis inferred from larval morphology. To describe the possible colonization history of R. sauteri in Taiwan, we propose hypotheses of within-island differentiation and a multiple-invasion model. Using a molecular clock, we estimated the order of divergence times between lineages in order to test the migration hypothesis. The multiple-invasion model was well supported by the phylogeny and a nested clade network.

To elucidate the molecular mechanisms involved in the delayed-type hypersensitivity (DTH) reaction, we performed a differential display analysis to identify genes whose expression was elevated in guinea pig DTH reaction-elicited skin-infiltrating cells. One of genes isolated was identified as a guinea pig I3 gene that encodes a polypeptide of 125 amino acids. The amino acid sequence was above 90% identical to that of human, mouse, and rat I3 protein. Although I3 was originally identified as a gene expressed in mouse brain, its mRNA was widely expressed in various guinea pig tissues and immune cells such as spleen cells and macrophages, but was hardly detected in thymic cells. I3 protein was also detected in immune cells, except for thymic cells. As expected from the amino acid sequence, part of the I3 protein was located on the cell surface. Furthermore, green fluorescent protein-tagged I3 protein showed a particulate localization in the cytoplasm and partly colocalized with lysosomes and late endosomes, coincident with the presence of typical endosomal/ lysosomal-targeting motifs. These results suggested that I3 may be involved in trafficking via the plasma membrane or in granule-related functions.

We sequenced a 1114-bp fragment of cytochrome b gene in six subspecies (115 samples) of Boa constrictor and detected 67 haplotypes. Our analyses revealed the presence of two distinct clades, one from Central America (CA) including the neighboring part of South America west of the Andes, and the other covering the rest of South America (SA). Sequence divergence between CA and SA clades is about 5–7%, which roughly corresponds to a separation at the time of uplift of the Colombian Andes following formation of the Panama Isthmus before 3.5 Myr Sequence divergence within the SA and CA clades is only 2–3%, suggesting a fairly recent spread of these clades into their current geographic ranges. Thus, we may not be dealing with taxa with a markedly old evolutionary history. Because juveniles of B. constrictor feed mostly on small rodents, we hypothesized that spread of this species was allowed by a new food source represented by muroid rodents that appeared after closure of the Panama portal. With respect to the taxonomy, B. c. imperator may be elevated to full species rank. Within the SA clade, a haplotype of Argentinian B. c. occidentalis is markedly distinct, while the remaining haplotype groups analyzed are distributed throughout large ranges and may all belong to a single nominotypic subspecies.

The morphology of the digestive system in fasting and refed Burmese pythons was determined, as well as the localization of the proton (H , K -ATPase) and sodium (Na , K -ATPase) pumps. In fasting pythons, oxyntopeptic cells located within the fundic glands are typically non-active, with a thick apical tubulovesicular system and numerous zymogen granules. They become active immediately after feeding but return to a non-active state 3 days after the ingestion of the prey. The proton pump, expressed throughout the different fasting/feeding states, is either sequestered in the tubulovesicular system in non-active cells or located along the apical digitations extending within the crypt lumen in active cells. The sodium pump is rapidly upregulated in fed animals and is classically located along the baso-lateral membranes of the gastric oxyntopeptic cells. In the intestine, it is only expressed along the lateral membranes of the enterocytes, i.e., above the lateral spaces and not along the basal side of the cells. Thus, solute transport within the intestinal lining is mainly achieved through the apical part of the cells and across the lateral spaces while absorbed fat massively crosses the entire height of the cells and flows into the intercellular spaces. Therefore, in the Burmese python, the gastrointestinal cellular system quickly upregulates after feeding, due to inexpensive cellular changes, passive mechanisms, and the progressive activation and synthesis of key enzymes such as the sodium pump. This cell plasticity also allows anticipation of the next fasting and feeding periods.

Estrogens are responsible for most characteristics of the female sex of a species, such as metabolic, behavioral, and morphological changes during reproduction. Artificial estradiol-17β (E2) treatment induces sex reversal in some fish. The Japanese pufferfish (Takifugu rubripes) has the most compact genome among vertebrates and great pottial for comparative genome analysis. In this paper, we describe the influence of E2 treatment during gonadal development in the pufferfish. After hatching, fry were treated with no (control) or a 0.1, 1, 10, or 100 μg/g diet from 21 to 80 days after hatching (dah). Doublesex-mab3-related transcription factor (DMRT1) is involved in testicular development. VASA is responsible for germ cell development, and CYP19A plays a role in E2 biosynthesis during ovarian development across animal phyla as well as in gonadal morphology after E2 treatment. DMRT1, VASA, and CYP19A were investigated in the gonads of E2-treated pufferfish. Fish fed with the highest dose (E2 100 µg/g diet) developed intersexual gonads in the testis; the majority of germ cells were oocytes, but some spermatocytes were detected. RT-PCR results showed the expression of VASA and CYP19A in all intersexual gonads and DMRT1 in some. Furthermore, abnormalities in the epithelium-tunica layer were detected, and gonadal somatic cells (e.g., granulosa cells, theca cells, or germinal epithelium) proliferated extensively in the intersexual gonad. These results suggest that E2 treatment induces ovarian development in the bipotential gonads of genetic males by modification of gonadal somatic cells and E2 production, mediated by CYP19A.

The genus Haplosyllides was considered as monotypic, with H. floridana as the only valid species. The present revision includes two more species in this genus: H. aberrans comb. nov. and H. ophiocomae sp. nov. Syllis (Haplosyllis) aberrans (from Vietnam) was considered a junior synonym of H. floridana (from the Caribbean). The finding of additional specimens from Vietnam and Indonesia, and the study of the type series, allowed us to redescribe H. aberrans comb. nov. on the basis of morphological, ecological and biogeographical characteristics. Haplosyllides aberrans comb. nov. differs from H. floridana in having posterior simple chaetae with tips twice as long, a pharyngeal tooth in all non-reproductive individuals, and the granules inside the dorsal cirri oval, elongated, and roughly distributed in longitudinal parallel rows. Haplosyllides ophiocomae sp. nov. was previously reported (as H. aberrans) from Puerto Rico. Although geographically close, it differs from H. floridana in having serration on the upper edge of the major teeth of simple chaetae, relatively shorter dorsal cirri, and a distinct mode of life. Haplosyllides floridana lives as an endosimbiont of Xetospongia muta, H. aberrans comb. nov. as a facultative parasite of Platycaris latirostris, and H. ophiocomae sp. nov. as a commensal of Ophiocoma pumila and other brittle stars. The meaning of these associations is discussed in light of the available information. The remaining records of “Haplosyllides aberrans” from the Marshall Islands (associated with corals of the genus Heliopora) and from Brazil (among corals and calcareous algae) are considered as doubtful.

The leafhopper genus Scaphotettix Matsumura is redescribed, and three new species are described and illustrated: S. striatus Dai and Zhang, sp. nov. from Java (on bamboo) and China; S. bispinosus Dai and Zhang, sp. nov from China; and S. pectinatus Dai and Zhang, sp. nov. from Vietnam. Most other species of Scaphotettix were re-examined and found to belong to a new genus also described herein, Scaphomonus Viraktamath, gen. nov.. The new genus is compared with the superficially similar Melanetettix Knight and Fletcher, Scaphodhara Viraktamath and Mohan, and Scaphoideus Uhler and a new species, Scaphomonus vateriae Viraktamath, sp. nov. from India, is described and illustrated. In addition, the following new combinations are proposed (all previously placed in Scaphotettix): Scaphomonus agumbensis (Viraktamath and Mohan) comb. nov.; S. arcuatus (Viraktamath and Mohan) comb. nov.; S. freytagi (Viraktamath and Mohan) comb. nov.; S. indicus (Distant) comb. nov.; S. longistylus (Li and Wang) comb. nov.; S. malnadicus (Viraktamath and Mohan) comb. nov.; S. quadrifidus (Viraktamath and Mohan) comb. nov.; S. redundans (Distant) comb. nov.; and S. splinterus (Li and Wang) comb. nov. Three species, Scaphotettix fanjingensis Li and Wang, Scaphotettix redstripeus Li and Wang, and Scaphotettix slenderus Li and Wang, do not belong to the genus Scaphotettix and are not treated further. Keys are provided for species of both Scaphotettix and Scaphomonus.

A new species of green freshwater hydra (Cnidaria, Hydrozoa: Hydrida), Hydra sinensis, is described from Guangdong Province, China. The chief distinction between H. sinensis sp. nov. and three other green hydras (H. hadleyi, H. viridissima, and H. plagiodesmica) is in the holotrichous isorhizae. Hydra sinensis sp. nov. differs from H. plagiodesmica in the shape of the holotrichous isorhizae, and from H. viridissima and H. hadleyi in the tubule of the capsule of the holotrichous isorhizae. The capsule tubule coils two times in 86% and three times in 14% of holotrichous isorhizae (n=50) in H. sinensis sp. nov.; we observed no tubules coiling four times. In contrast, the capsule tubule coils three or four times in H. viridissima and H. hadleyi, and no tubules coiling two times have been reported. In addition, holotrichous isorhizae, which are mainly located around the hypostome, are sparse in the tentacles of H. sinensis sp. nov., whereas the majority of holotrichous isorhizae is located on the tentacles in most other hydras. A molecular phylogenetic analysis using the nuclear small subunit (18S) ribosomal RNA gene indicated a close relationship between H. sinensis and H. viridissima. Hydra viridissima did not group within a clade of four individuals of H. sinensis, indicating a possible sister-species relationship between the two species. Morphological characters in combination with the molecular phylogenetic evidence support Hydra sinensis as a new species.