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Reproductive traits of the Ryukyu long-furred rat (Diplothrix legata) on Okinawa-jima Island.

Okano T, Nakata K, Nakaya Y, Nagamine T, Onuma M - J. Vet. Med. Sci. (2015)

Bottom Line: This animal is endangered as a result of deforestation, predation by introduced carnivores and mortality caused by vehicles.Seminiferous diameter of adult was significantly small (136 ± 28 µm, n=8) from April to August.These results provide fundamental knowledge that will be beneficial for in situ and ex situ conservation of this rare species.

View Article: PubMed Central - PubMed

Affiliation: Ecological Genetics Analysis Section, Center for Environmental Biology and Ecosystem Studies, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan.

ABSTRACT
The Ryukyu long-furred rat, Diplothrix legata, is a large rodent distributed only on Amami-ohshima Island, Tokuno-shima Island and Okinawa-jima Island, Japan. This animal is endangered as a result of deforestation, predation by introduced carnivores and mortality caused by vehicles. We performed theriogenological examinations of 32 male and 25 female Ryukyu long-furred rats carcasses collected from wild populations on northern Okinawa-jima Island from December 2005 to September 2013. Adult males had remarkably large preputial glands. Seminiferous diameter of adult was significantly small (136 ± 28 µm, n=8) from April to August. Numerous spermatozoa were observed from September through February, and seminiferous diameter was significantly large (216 ± 27 µm, n=12) during this time in adults; testes length changed in a similar pattern. These findings indicate that the mating season may occur from September through February. Size (body length) at sexual maturity was estimated to be >560 mm in both sexes. From observation of corpora lutea and placental scars, litter size was estimated to range from 2 to 12 (average=6, n=4). These results provide fundamental knowledge that will be beneficial for in situ and ex situ conservation of this rare species.

No MeSH data available.


Related in: MedlinePlus

Seminiferous tubules of adult Ryukyu long-furred rats in the estimated non-mating(May; A, B) and mating (October; C, D) seasons. (B) and (D) are high maginificationfigures of (A) and (C), respectively. Se, Sertoli cells; Spg, spermatogonia; Spc,spermatocytes; rSp, round spermatids; Sp, elongate spermatids. Hematoxylin and eosinstaining.
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fig_005: Seminiferous tubules of adult Ryukyu long-furred rats in the estimated non-mating(May; A, B) and mating (October; C, D) seasons. (B) and (D) are high maginificationfigures of (A) and (C), respectively. Se, Sertoli cells; Spg, spermatogonia; Spc,spermatocytes; rSp, round spermatids; Sp, elongate spermatids. Hematoxylin and eosinstaining.

Mentions: Testes: Seasonal changes in seminiferous tubule diameter and testes lengthin adult males are shown in Fig. 4. Theseminiferous tubule diameter in adult was significantly small (136 ± 28 µm,n=8) from April to August and significantly large (216 ± 27 µm, n=12) fromSeptember to February (Fig. 4A). From April toAugust, three out of eight adult rats had no spermatozoa in the seminiferous tubules, andtheir seminiferous tubules contained Sertoli cells and germ cells from spermatogonia todegenerating round spermatids (Fig. 5A and 5BFig. 5.


Reproductive traits of the Ryukyu long-furred rat (Diplothrix legata) on Okinawa-jima Island.

Okano T, Nakata K, Nakaya Y, Nagamine T, Onuma M - J. Vet. Med. Sci. (2015)

Seminiferous tubules of adult Ryukyu long-furred rats in the estimated non-mating(May; A, B) and mating (October; C, D) seasons. (B) and (D) are high maginificationfigures of (A) and (C), respectively. Se, Sertoli cells; Spg, spermatogonia; Spc,spermatocytes; rSp, round spermatids; Sp, elongate spermatids. Hematoxylin and eosinstaining.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4488399&req=5

fig_005: Seminiferous tubules of adult Ryukyu long-furred rats in the estimated non-mating(May; A, B) and mating (October; C, D) seasons. (B) and (D) are high maginificationfigures of (A) and (C), respectively. Se, Sertoli cells; Spg, spermatogonia; Spc,spermatocytes; rSp, round spermatids; Sp, elongate spermatids. Hematoxylin and eosinstaining.
Mentions: Testes: Seasonal changes in seminiferous tubule diameter and testes lengthin adult males are shown in Fig. 4. Theseminiferous tubule diameter in adult was significantly small (136 ± 28 µm,n=8) from April to August and significantly large (216 ± 27 µm, n=12) fromSeptember to February (Fig. 4A). From April toAugust, three out of eight adult rats had no spermatozoa in the seminiferous tubules, andtheir seminiferous tubules contained Sertoli cells and germ cells from spermatogonia todegenerating round spermatids (Fig. 5A and 5BFig. 5.

Bottom Line: This animal is endangered as a result of deforestation, predation by introduced carnivores and mortality caused by vehicles.Seminiferous diameter of adult was significantly small (136 ± 28 µm, n=8) from April to August.These results provide fundamental knowledge that will be beneficial for in situ and ex situ conservation of this rare species.

View Article: PubMed Central - PubMed

Affiliation: Ecological Genetics Analysis Section, Center for Environmental Biology and Ecosystem Studies, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan.

ABSTRACT
The Ryukyu long-furred rat, Diplothrix legata, is a large rodent distributed only on Amami-ohshima Island, Tokuno-shima Island and Okinawa-jima Island, Japan. This animal is endangered as a result of deforestation, predation by introduced carnivores and mortality caused by vehicles. We performed theriogenological examinations of 32 male and 25 female Ryukyu long-furred rats carcasses collected from wild populations on northern Okinawa-jima Island from December 2005 to September 2013. Adult males had remarkably large preputial glands. Seminiferous diameter of adult was significantly small (136 ± 28 µm, n=8) from April to August. Numerous spermatozoa were observed from September through February, and seminiferous diameter was significantly large (216 ± 27 µm, n=12) during this time in adults; testes length changed in a similar pattern. These findings indicate that the mating season may occur from September through February. Size (body length) at sexual maturity was estimated to be >560 mm in both sexes. From observation of corpora lutea and placental scars, litter size was estimated to range from 2 to 12 (average=6, n=4). These results provide fundamental knowledge that will be beneficial for in situ and ex situ conservation of this rare species.

No MeSH data available.


Related in: MedlinePlus