Effects of Ecdysterone and C&lt;SUB&gt;18&lt;/SUB&gt;-Juvenile Hormone on Spermatogenesis in the Silkworm Larva, Bombyx mori L.

Mitsui, Takashi; Nobusawa, Chieko; Fukami, Jun-ichi; Fukunaga, Kimitoshi

doi:10.1303/aez.11.344

Cited by 10 publications

(5 citation statements)

References 13 publications

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“…Spermatogenesis proceeds uninterrupted in cultured testes of 4th and 5th instar larvae of the codling moth in a medium containing mammalian serum but neither hemolymph nor hormones. Similar results were reported for Galleria mellonella [19], and Bombyx mori [18]. In similar media, however, spermatogenesis does not proceed in testes of diapausing pupae unless the testicular wall is peeled off and the naked cysts come into direct contact with the medium [20].…”

Section: Resultssupporting

confidence: 84%

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The Eupyrene-Apyrene Dichotomous Spermatogenesis of Lepidoptera. Organ Culture Study on the Timing of Apyrene Commitment in the Codling Moth

Friedländer

Benz

1981

International Journal of Invertebrate Reproduction

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Lepidopteran spermatogenesis is dichotomous, producing eupyrene (nucleated) and apyrene (anucleated) spermatozoa. The eupyrene precedes the apyrene spermatogenesis. The timing of the switchover from eupyrene to apyrene spermatogenesis was determined by cultivating testes of accurately aged codling moth larvae in a medium containing mammalian serum but neither hemolymph nor insect hormones. In cultures, eupyrene sper· matogenesis occurred in testes dissected from either 4th or 5th instar larvae, probably due to macromolecular factor-like activity of the serum of the medium. But apyrene spermatogenesis occurred only in testes explanted during or after the fourth day of the 5th instar larva. It is concluded that: (1) An apyrene spermatogenesis inducing factor (ASIF) becomes active on the fourth day of the 5th instar larva in addition to the already existing macromolecular factor. (2) Primary spermatocytes can develop into either eupyrene or apyrene spermatozoa. (3) The apyrene spermatogenesis commitment and pupal commitment of other tissues coincide about the fourth day of the 5th instar larva.

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Section: Resultssupporting

confidence: 84%

“…The ASIF differs from the macromolecular factor (MF), which is necessary for both inducing and sustaining spermatogenesis in cultured testes of diapausing [16,17] and non-diapausing [18] Lepidoptera. We suppose that the MF, too, was present in the medium we used as it contains mammalian serum which is known to have MF-like activity [17].…”

Section: Resultsmentioning

confidence: 99%

The Eupyrene-Apyrene Dichotomous Spermatogenesis of Lepidoptera. Organ Culture Study on the Timing of Apyrene Commitment in the Codling Moth

Friedländer

Benz

1981

International Journal of Invertebrate Reproduction

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“…Reports on the role of ecdysteroids in spermatogenesis are contradictory and the results tend to depend on the developmental stage of the animal. Initiation of sperm development in larval stages might not require ecdysteroids, as shown here and as indicated by other authors [12,13]. In contrast, reinitiation of spermatogenesis after larval or pupal diapause was stimulated by addition of ecdysteroids to the culture in several species of insects [ 9-11 ,28].…”

Section: Specificity Of the Sheath Effectsupporting

confidence: 77%

“…Ecdysteroids seem to increase spermatogonial mitotic rate in Rhodnius and locusts [7,8] and initiate meiosis or elongation of spermatocysts [9][10][11] in diapausing lepidopteran pupae, but they are not necessary in other species [12,13]. Other factors have also been reported to promote spermatogenesis in vitro.…”

Section: Introductionmentioning

confidence: 99%

In VitroSpermatogenesis in Lepidopteran Larvae: Role of the Testis Sheath

Giebultowicz

Loeb

Bořkovec

1987

International Journal of Invertebrate Reproduction and Developm

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Premeiotic spermatocysts from testes of Heliothis virescens larvae were cultured in vitro. These eupyrene cysts progressed through meiosis and elongation in a medium containing calf serum in the absence of ecdysteroids. However, they also required the presence of the testis sheaths. The spermatogenesis-promoting effect of testis sheaths was dose dependent and varied with the donor's age. The active material was extractable from the tissue and was heat stable. ecdysteroid, spermatocyst, meiosis, Heliothis virescens, Lymantria dispar IntroductionGerm cells of insects develop as clones. A species-specific number of mitotic divisions produce round spermatocysts which later progress through meiotic divisions and differentiate into spermatozoa within the elongated spermatocyst (reviewed by Phillips [1] and Roosen-Runge [2]). Usually, spermatogenesis starts in the late larval instars and proceeds on a schedule well correlated with the insect's metamorphosis [3]. Ever since the pioneering work of Goldsmith [4], who first induced differentiation of spermatocysts in vitro in pupal hemolymph as medium, many reports have been published concerning factors which regulate development of insect sperm (reviewed by

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“…In some insects, ecdysteroids influences spermatogenesis ( Mitsui et al 1976 ). Our observation that AKR2E4 is located in the testes of B. mori suggests that it may also have an effect on spermatogenesis.…”

Section: Resultsmentioning

confidence: 99%

Localization of an Aldo-Keto Reductase (AKR2E4) in the Silkworm Bombyx mori (Lepidoptera: Bombycidae)

Yamamoto

Ozakiya

Uno

2017

Journal of Insect Science

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The aldo-keto reductase AKR2E4 reduces 3-dehydroecdysone to ecdysone in the silkworm Bombyx mori L. In this study, a quantitative polymerase chain reaction analysis revealed that the level of AKR2E4 mRNA was higher in the testes than in other tissues, and a western immunoblot analysis revealed that the AKR2E4 content in the testes was stage-specific from the fifth larval instar to the pupal stage. Immunohistochemical analysis showed that the AKR2E4 protein was present in cyst cells associated with sperm cells and spermatocytes. These results indicate that AKR2E4 plays an important role in 3-dehydroecdysone conversion to ecdysone and spermatogenesis in silkworm testes.

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Effects of Ecdysterone and C<SUB>18</SUB>-Juvenile Hormone on Spermatogenesis in the Silkworm Larva, Bombyx mori L.

Cited by 10 publications

References 13 publications

The Eupyrene-Apyrene Dichotomous Spermatogenesis of Lepidoptera. Organ Culture Study on the Timing of Apyrene Commitment in the Codling Moth

The Eupyrene-Apyrene Dichotomous Spermatogenesis of Lepidoptera. Organ Culture Study on the Timing of Apyrene Commitment in the Codling Moth

In VitroSpermatogenesis in Lepidopteran Larvae: Role of the Testis Sheath

Localization of an Aldo-Keto Reductase (AKR2E4) in the Silkworm Bombyx mori (Lepidoptera: Bombycidae)

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