scholarly journals Destination of apyrene sperm following migration from the bursa copulatrix in the monandrous swallowtail butterfly Byasa alcinous

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Tatsuro Konagaya ◽  
Naoto Idogawa ◽  
Mamoru Watanabe
Keyword(s):  
Sperm Storage ◽  
Bursa Copulatrix ◽  
Swallowtail Butterfly ◽  
Storage Organs ◽  
Apyrene Sperm ◽  
Eupyrene Sperm ◽  
Spermathecal Gland

AbstractMost male lepidopterans produce fertile eupyrene sperm and non-fertile apyrene sperm, both of which are transferred to the female in a spermatophore during mating. Apyrene sperm outnumbers eupyrene sperm and both sperm types migrate from the bursa copulatrix to the spermatheca after mating. While eupyrene sperm are maintained in the spermatheca until oviposition, the number of apyrene sperm decreases with time. It is unclear whether apyrene sperm disappear from all sperm storage organs in females because both sperm types are often observed in the spermathecal gland. To investigate this, the numbers of both sperm types were estimated in the spermatheca and spermathecal gland of female Byasa alcinous (a monandrous butterfly) 6, 12, 48, 96, and 192 h after mating terminated. Apyrene sperm arrived in the spermatheca earlier than eupyrene sperm; however, some eupyrene and apyrene sperm migrated to the spermathecal gland from the spermatheca at almost the same time. The number of apyrene sperm reached a peak 12 h after the termination of mating and then decreased with time in both the spermatheca and spermathecal gland. Our results suggest that the role of apyrene sperm might be completed early after arriving in the spermatheca of B. alcinous.

scholarly journals Double copulation of a female with sterile diploid and polyploid males recovers fertility in Bombyx mori

Zygote ◽  
2002 ◽  
Vol 10 (1) ◽  
pp. 23-29 ◽  
Author(s):  
Ken Sahara ◽  
Naoko Kawamura
Keyword(s):  
Heat Shock ◽  
Microscopic Observation ◽  
Experimental System ◽  
Reproductive Organs ◽  
Sperm Function ◽  
Apyrene Sperm ◽  
Eupyrene Sperm ◽  
Female Reproductive Organs ◽  
Diploid Sperm

Silkworm males produce dimorphic sperm, nucleate eupyrene sperm and anucleate apyrene sperm. Apyrene sperm have been speculated to have an assisting role in fertilisation. However, the coexistence of eupyrene and apyrene sperm in the testis and female reproductive organs has made it difficult to define the role of apyrene sperm. Polyploid males are highly sterile. Microscopic observation revealed that the elimination of eupyrene nuclei by peristaltic squeezing caused the sterility of polyploids. Heat-shock applied to pupae of Daizo males (DH) also induced high sterility due to the lack of normal apyrene sperm. When eupyrene sperm of sterile DH males and apyrene sperm of sterile polyploid males were mixed by double copulation, a remarkable increase in fertility of the double-mated females was observed. This finding strongly suggests that the apyrene sperm are indispensable in fertilisation of the silkworm and that polyploid apyrene sperm function as a substitute for diploid sperm. We established an experimental system in which we can separate the two types of sperm for further studies on their functions without chemical and/or mechanical treatments.

Structural comparison between eupyrene and apyrene spermiogenesis in Calpodes ethlius (Hesperiidae, Lepidoptera)

1982 ◽  
Vol 60 (6) ◽  
pp. 1216-1230 ◽  
Author(s):  
J. Lai-Fook
Keyword(s):  
Plasma Membrane ◽  
Reproductive Tract ◽  
Condensed Chromatin ◽  
Bursa Copulatrix ◽  
Testicular Sperm ◽  
Structural Comparison ◽  
Reticular System ◽  
Apyrene Sperm ◽  
Eupyrene Sperm ◽  
Spherical Nuclei

Calpodes ethlius, like other Lepidoptera, produce two kinds of sperm, nucleated eupyrene and anucleated apyrene. The latter lack not only a nucleus but also reticular lacinate appendages at maturity in the testis. It is, however, possible to distinguish between them much earlier as secondary spermatocytes. The larger eupyrene spermatocytes have larger, spherical nuclei with dispersed chromatin, while the smaller apyrene spermatocytes have smaller more oval nuclei with clumped chromatin. A more extensive perinuclear reticular system surrounds the eupyrene nucleus. The nucleus of the eupyrene spermatid is small with condensed chromatin; however, the apyrene spermatid contains many micronuclei which are later cytolysed and eliminated. An acrosome forms in the eupyrene spermatid and differentiates into a tubular structure which extends along the elongating nucleus, in which the chromatin simultaneously undergoes characteristic changes in distribution and condensation. The reticular appendage first appears extracellularly where the acrosome makes contact with the plasma membrane, and later extends the full length of the sperm. The lacinate appendages appear much later, after elongation of head and of the tail are completed. The mature testicular sperm are distinguishable on the basis of detailed differences in mitochondrial derivatives, and axonemal structure. The free apyrene sperm undergo fewer changes than do the still encysted eupyrene sperm as they pass from the testis into the reproductive tract and finally into the bursa copulatrix of the female.

scholarly journals Expression of Mst89B and CG31287 is Needed for Effective Sperm Storage and Egg Fertilization in Drosophila

Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 289
Author(s):  
Gurman Grewal ◽  
Bahar Patlar ◽  
Alberto Civetta
Keyword(s):  
Germ Line ◽  
Sperm Storage ◽  
Mature Sperm ◽  
Sperm Production ◽  
Cytogenetic Map ◽  
Egg Hatchability ◽  
Storage Organs ◽  
Competitive Success ◽  
Paternity Success ◽  
And Storage

In Drosophila, male reproductive fitness can be affected by any number of processes, ranging from development of gametes, transfer to and storage of mature sperm within the female sperm storage organs, and utilization of sperm for fertilization. We have previously identified the 89B cytogenetic map position of D. melanogaster as a hub for genes that effect male paternity success when disturbed. Here, we used RNA interference to test 11 genes that are highly expressed in the testes and located within the 89B region for their role in sperm competition and male fecundity when their expression is perturbed. Testes-specific knockdown (KD) of bor and CSN5 resulted in complete sterility, whereas KD of CG31287, Manf and Mst89B, showed a breakdown in sperm competitive success when second to mate (P2 < 0.5) and reduced fecundity in single matings. The low fecundity of Manf KD is explained by a significant reduction in the amount of mature sperm produced. KD of Mst89B and CG31287 does not affect sperm production, sperm transfer into the female bursa or storage within 30 min after mating. Instead, a significant reduction of sperm in female storage is observed 24 h after mating. Egg hatchability 24 h after mating is also drastically reduced for females mated to Mst89B or CG31287 KD males, and this reduction parallels the decrease in fecundity. We show that normal germ-line expression of Mst89B and CG31287 is needed for effective sperm usage and egg fertilization.

scholarly journals Functional morphology of immature mating in a widow spider

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Lenka Sentenská ◽  
Aileen Neumann ◽  
Yael Lubin ◽  
Gabriele Uhl
Keyword(s):  
Sperm Competition ◽  
Storage Conditions ◽  
Sperm Storage ◽  
Sperm Transfer ◽  
Costs And Benefits ◽  
Micro Computed Tomography ◽  
Mating Tactics ◽  
Adult Females ◽  
Storage Organs ◽  
Widow Spider

Abstract Background Mating generally occurs after individuals reach adulthood. In many arthropods including spiders, the adult stage is marked by a final moult after which the genitalia are fully developed and functional. In several widow spider species (genus Latrodectus), however, immature females may mate a few days before they moult to adulthood, i.e. in their late-subadult stage. While the “adult” mating typically results in cannibalism, males survive the “immature” mating. During both “immature” and “adult” matings, males leave parts of their paired copulatory organs within female genitalia, which may act as mating plugs. To study potential costs and benefits of the two mating tactics, we investigated female genital morphology of the brown widow spider, L. geometricus. Light microscopy, histology and micro-computed tomography of early-subadult, late-subadult and adult females were conducted to determine the overall pattern of genital maturation. We compared genitalia of mated late-subadult and adult females to reveal potential differences in the genitalic details that might indicate differential success in sperm transfer and different environments for sperm storage and sperm competition. Results We found that the paired sperm storage organs (spermathecae) and copulatory ducts are developed already in late-subadult females and host sperm after immature mating. However, the thickness of the spermathecal cuticle and the staining of the secretions inside differ significantly between the late-subadult and adult females. In late-subadult females mating plugs were found with higher probability in both spermathecae compared to adult females. Conclusions Sperm transfer in matings with late-subadult females follows the same route as in matings with adult females. The observed differences in the secretions inside the spermathecae of adult and late-subadult females likely reflect different storage conditions for the transferred sperm which may lead to a disadvantage under sperm competition if the subadult female later re-mates with another male. However, since males mating with late-subadult females typically transfer sperm to both spermathecae they might benefit from numerical sperm competition as well as from monopolizing access to the female sperm storage organs. The assessment of re-mating probability and relative paternity will clarify the costs and benefits of the two mating tactics in light of these findings.

scholarly journals EVOLUTION OF MULTIPLE KINDS OF FEMALE SPERM-STORAGE ORGANS INDROSOPHILA

Evolution ◽  
1999 ◽  
Vol 53 (6) ◽  
pp. 1804-1822 ◽  
Author(s):  
Scott Pitnick ◽  
Therese Marrow ◽  
Greg S. Spicer
Keyword(s):  
Sperm Storage ◽  
Storage Organs

Multiple Matings and Sperm Competition

2020 ◽  
pp. 332-363
Author(s):  
Carola Becker ◽  
Raymond T. Bauer
Keyword(s):  
Genetic Diversity ◽  
Sperm Competition ◽  
Mate Guarding ◽  
Sperm Storage ◽  
Internal Fertilization ◽  
Multiple Matings ◽  
Storage Organs ◽  
Anatomical Adaptations ◽  
Multi Level ◽  
Molecular Aspects

In polyandrous mating systems, females mate multiple times and males have evolved adaptations for sperm competition which increase the number and fitness of their offspring. Mate guarding is a widespread monopolization strategy in groups where female receptivity is temporally restricted and often associated with the molt. Precopulatory guarding occurs in branchipods, copepods, peracarids and decapods. Postcopulatory guarding is notable in numerous brachyurans with males protecting females until her exoskeleton has hardened. During copulation, male success in fertilization depends on an effective sperm transfer mechanism, the precise placement of ejaculates closest to where female gametes are fertilized. Male copulatory systems are highly diverse and strongly adapted to these tasks, especially the structures that interact with the female genital ducts. The elaborate tips of brachyuran gonopods are supposed to act in the displacement, possibly even in the removal of rival sperm masses; however, sperm removal is only evident in crayfish: males eat spermatophores previously deposited by other males. During copulation of several crustacean groups, males transfer secretions that harden and form a sealant. These sperm plugs, plaques and gel layers may protect their own sperm, prevent remating or seal off rival sperm from the site of fertilization. Several groups of isopods and decapods have internal insemination, elaborate sperm storage organs and some exhibit internal fertilization. The intensity of sperm competition increases with the latency between the processes of insemination and fertilization. This chapter gives on overview on mate guarding, male sealants and the anatomical adaptations to sperm competition in crustaceans. We also briefly discuss the consequences of multiple matings for the genetic diversity of broods, i.e., single vs. multiple paternities. There is still a lack of data for many crustacean groups. Moreover, it is often hard to assess how successful a male strategy to ensure paternity actually is as many studies focus on either the behavioral, anatomical, or molecular aspects, while comprehensive multi-level studies on crustacean sperm competition are virtually absent from the literature.

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