Background One genetic mechanism known to be associated with autism spectrum disorders (ASD) is chromosomal abnormalities. The identification of copy number variants (CNV), i.e., microdeletions and ...microduplications that are undetectable at the level of traditional cytogenetic analysis, allows the potential association of submicroscopic chromosomal imbalances and human disease. Methods We performed array comparative genomic hybridization (aCGH) utilizing a 19K whole genome tiling path bacterial artificial chromosome (BAC) microarray on 397 unrelated subjects with autism spectrum disorder. Common CNV were excluded using a control group comprised of 372 individuals from the National Institute of Mental Health (NIMH) Genetics Initiative Control samples. Confirmation studies were performed on all remaining CNV using fluorescence in situ hybridization (FISH), microsatellite analysis, and/or quantitative polymerase chain reaction (PCR) analysis. Results A total of 51 CNV were confirmed in 46 ASD subjects. Three maternal interstitial duplications of 15q11-q13 known to be associated with ASD were identified. The other 48 CNV ranged in size from 189 kilobase (kb) to 5.5 megabase (Mb) and contained from 0 to ∼40 National Center for Biotechnology Information (NCBI) Reference Sequence (RefSeq) genes. Seven CNV were de novo and 44 were inherited. Conclusions Fifty-one autism-specific CNV were identified in 46 of 397 ASD patients using a 19K BAC microarray for an overall rate of 11.6%. These microdeletions and microduplications cause gene dosage imbalance in 272 genes, many of which could be considered as candidate genes for autism.
The fourspine sculpin Cottus kazika is indigenous to Japan and found in Honshu except for the waters facing the Seto Inland Sea, and was also found in southern Shikoku and eastern Kyushu. This ...species has a catadromous lifestyle and migrates as juveniles from the sea to the middle reaches of rivers to grow. The growth pattern of this fish was investigated by a mark-and-recapture method from July 1994 to December 1996, in the Nigorikawa River, a tributary of the Gonokawa River system, Shimane Prefecture. 0-year-old fish of 50-70 mm total length (TL) occurred in the study area from June to July, grew to 90-140 mm TL by the following April, and attained 160-210 mm TL by December. This fish grew rapidly in September-November and April-July, almost ceasing to grow in July-September. It seems that this stagnant growth phase in summer is a characteristic of the seasonal growth pattern of C. kazika. A rearing experiment indicated that the growth rate of C. kazika was higher at 16-22 deg C than at 12-14 and 24-26 deg C. This result supports the field evidence of a stagnant growth phase in summer in the Nigorikawa River.
"The spawning grounds of a cottid fish, Trachidermus fasciatus, were investigated off the mouth of the Kashima River in Ariake Bay from January to March, 1996-1999. The nests were found about 1.1-2.3 ...km off the mouth of the river, where the bottom salinity was 8 per mille - 21 per mille at low tides. Oyster shells were mainly found to be used as nests. A male, a pair, a male and egg clusters, a pair and egg clusters, or a female were found inside shells. The average number of guarded egg clusters per male in shells was 1.3 =+- 0.4."
Embryonic, larval and juvenile development of the catadromous roughskin sculpin,Trachidermus fasciatus, were described using eggs spawned in an aquarium. The eggs, measuring 1.98–2.21 mm in diameter, ...were light reddish-yellow and had many oil globules, 0.05–0.18 mm in diameter. Hatching occurred 30 days after spawning at 2.3–11.3°C. The newly-hatched larvae, measuring 6.9–7.3 mm BL, had a single oil globule, 9–10+25–26=34–36 myomeres and 6 or 7 large stellate melanophores dorsally along the gut. The yolk was almost resorbed, number of pectoral-fin rays attained 16–17, and two parietal, one nuchal and four preopercular spines were formed, 5 days after hatching, at 8.2–8.4 mm BL. The oil globule disappeared, and one supracleithral spine was formed, 11 days after hatching, at 8.9–9.5 mm BL. Notochord flexion began 15 days after hatching, at 9.7–10.3 mm BL. A posttemporal spine was formed 20 days after hatching, at 10.7–10.9 mm BL. The first dorsal fin spines (VII–VIII), second dorsal fin and anal fin rays (18–19, 16–18, respectively) appeared 23 days after hatching, at 12.0–13.7 mm BL. The pelvic fin spine and rays (I, 4) were formed and black bands on the head and sides of the body began to develop 27 days after hatching, at 13.8–15.8 mm BL.Newly-hatched larvae swam just below the surface in the aquaria. Preflexion larvae (8.9–9.5 mm BL), in which the oil globule had disappeared, swam in the middle layer, while juveniles (13.8–15.8 mm BL) began swimming on the bottom of the aquaria. Swimming behavior observed in the aquaria suggested that the fish started to change to a demersal existence at the juvenile stage.
The seven species of freshwater sculpins inhabiting the Japanese Archipelago (6 Cottus and 1 Trachidermus) exhibit various life history characteristics, such as catadromous, amphidromous, lacustrine ...and fluvial (Goto, 1990). Both the fourspine sculpin, C. kazika, and roughskin sculpin, T. fasciatus, have a catadromous life style. The former is indigenous to Japan, being found in Honshu, Shikoku and Kyushu Islands. The species migrates from the middle and lower reaches of rivers to the sea for spawning in late autumn and winter (Miyadi et al., 1976; Nakamura, 1963). However, little is known about its reproductive ecology, the only available evidence being a collection of egg clusters and attending males taken at the mouth of the Nagara River, where salinity ranged from 16 to 18 ppt (River Bureau, Ministry of Construction and Water Resources Development Public Corporation, 1992). This paper reports further aspects of the reproductive ecology of C. kazika.
The embryonic, larval and juvenile development of blue whiting,Sillago parvisquamis Gill, are described from a series of laboratory-reared specimens. Mean egg diameter and mean total length (TL) of ...newly-hatched larvae were 0.71 mm and 1.58 mm, respectively. The eggs were non-adhesive, buoyant and spherical with an oil globule (mean diameter 0.18 mm). Hatching occurred about 20 hours after fertilization at a temperature of 24.0-25.0°C, newly-hatched larvae having 38-40 myomeres. The yolk and oil globule were completely absorbed 3 days after hatching at 2.8-3.2 (mean 3.0) mm TL. Notochord flexion was completed by 7.2-8.2 (7.7) mm TL, and pectoral and caudal fin rays fully developed by approximately 10 mm and 8.5 mm TL, respectively. Completion of fin development occurred in the following sequence: caudal, pectoral, anal and second dorsal, first dorsal and pelvic, the last-mentioned by approximately 11 mm TL. The larvae ofS. parvisquamis andS. japonica, which closely resemble each other in general morphology and pigmentation, could be distinguished as follows. Newly-hatchedS. parvisquamis larvae had more myomeres thanS. japonica (38-40 vs. 32-34) and more melanophores on the dorsal surface of the body (19-28 vs. about 40).Sillago japonica had a vertical band of melanophores on the caudal peduncle, which was lacking in postflexionS. parvisquamis larvae. In addition, juveniles ofS. parvisquamis (larger than 23 mm TL) had melanophores on the body extending anteriorly to below the lateral line to form a midlateral band, whereas no obvious band occurred on similarly-sizedS. japonica juveniles.PUBLICATION ABSTRACT
The specific gravities of the ayu Plecoglossus altivelis larvae were measured in a series of saline solutions. The volume of swim bladder and wet and dry fish weight were also measured. After ...decresasing from 1.038 to 1.032 through the prelarval period, the specific gravity of postlarvae with uninflated swim bladder increased to 1.050. The larvae began to inflate their swim bladder while 15 to 20mm TL during the nighttime and 21 to 35mm TL during the daytime. With inflation of the swim bladder, the specific gravity decreased remarkably and its diel change became to be marked, by day-increase and night-decrease. Buoyancy regulation was effected by the change of the swim bladder volume, which was induced by a photocycle, viz. light-deflation and dark-infla-tion. The gas in the swim bladder originated from the air swallowed at the water surface. These results suggest that ayu larvae display diel vertical migration, viz. dusk-upward and dawn-downward, similar to several physostomous species such as anchovy and herring.
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