Mother-to-embryo vitellogenin transport in a viviparous teleost Xenotoca eiseni

魚類がお腹の子供に与える栄養素を解明 --哺乳類が失った遺伝子を利用して胎生機構を獲得--. 京都大学プレスリリース. 2019-10-09.Vitellogenin (Vtg), a yolk nutrient protein that is synthesized in the livers of female animals, and subsequently carried into the ovary, contributes to vitellogenesis in oviparous animals. Thus, Vtg levels are elevated during oogenesis. In contrast, Vtg proteins have been genetically lost in viviparous mammals, thus the yolk protein is not involved in their oogenesis and embryonic development. In this study, we identified Vtg protein in the livers of females during the gestation of the viviparous teleost, Xenotoca eiseni. Although vitellogenesis is arrested during gestation, biochemical assays revealed that Vtg protein was present in ovarian tissues and lumen fluid. The Vtg protein was also detected in the trophotaeniae of the intraovarian embryo. Immunoelectron microscopy revealed that Vtg protein is absorbed into intracellular vesicles in the epithelial cells of the trophotaeniae. Furthermore, extraneous Vtg protein injected into the abdominal cavity of a pregnant female was subsequently detected in the trophotaeniae of the intraovarian embryo. Our data suggest that the yolk protein is one of the matrotrophic factors supplied from the mother to the intraovarian embryo during gestation in X. eiseni

Surgery to improve hearing of a preschool child with profound bilateral deafness

Hearing loss in children under school age adversely effects speech and personality development. It is possible to improve conductive hearing loss by surgery, but difficult to improve combined hearing loss. The authors succeeded surgically improving the hearing of a 5 year-old boy suffering from speech retardation due to bilateral congenital combined hearing loss. The improvement in hearing aided speech training. He has graduated from schools for the deaf (primary, middle and senior high school). His I.Q. is 70 or less. The average hearing is in the speech range of 90 dB bilaterally, showing combined hearing loss by play audiometry. At the age of 1.5 years, he was suspected of having congenital aural atresia on the right side, congenital narrow ear canal on the left side and minor anomalies of the auricles bilaterally, including congenital aural fistulas. His mother and younger brother also suffer from bilateral congenital combined hearing loss. The tympanotomy on the left ear revealed severe anomalies, such as omega shaped ossicle composed of the malleus and incus joined to the posterior bony wall of external auditory canal and bony fixation of the stapes footplate. The bulky ossicle was mobilized by cutting the junction to the bony canal wall, and a small fenestra stapedectomy was performed. A tympanotomy on the right ear was also performed, but irregular development of the inner ear prevented the possibility of obtaining hearing improvement. The authors discussed the possibility and significance of surgery to improve hearing even in cases of profound combined hearing loss in preschool children

Additional file 2: Figure S1. of Past seawater experience enhances seawater adaptability in medaka, Oryzias latipes

Changes in gene expressions of Na+/K+-ATPase α-subunits 1a (A), α1c (B), α2 (C) and α3a (D) after direct SW transfer of SW-experienced medaka (solid circles) and control FW medaka (open circles). Values are means ± SEM. Numerals in parentheses indicate the number of samples examined. Different letters indicate significant differences within the same group (ANOVA, Tukey-Kramer multiple comparison test, p < 0.05). Asterisks indicate significant differences between the two groups at the same time points (two-sided Student’s t test, *p < 0.05 and **p < 0.01). (TIF 5121 kb

Additional file 1: Table S1. of Past seawater experience enhances seawater adaptability in medaka, Oryzias latipes

Primers used for cloning and real-time qPCR analyses. (XLSX 11 kb