CERTAIN ASPECTS OF THE CENTRIOLE ADJUNCT, SPERMIOGENESIS, AND THE MATURE SPERM OF INSECTS

1966 ◽  
Vol 8 (4) ◽  
pp. 759-773 ◽  
Author(s):  
Osmond P. Breland ◽  
George Gassner III ◽  
Robert W. Riess ◽  
John J. Biesele
Keyword(s):  
Mature Sperm ◽  
Centriole Adjunct

Spermatogenesis in the Dragonfly with Particular Reference to the Cytoplasmic Organelles

1972 ◽  
Vol 30 ◽  
pp. 110-111
Author(s):  
Sant S. Sekhon
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
Mature Sperm ◽  
Electron Microscopic ◽  
Cytoplasmic Organelles ◽  
Microscopic Studies ◽  
Insect Sperm ◽  
Large Round

Although there have been numerous studies concerning the morphogenetic changes accompanying the maturation of insect sperm, only a few deal with the sperm differentiation in the dragonflies. In two recent electron microscopic studies Kessel, has comprehensively treated the erlationship of microtubules to the nucleus and mid-piece structures during spermiogenesis in the dragonfly. The purpose of this study is to follow the sequential nuclear and cytoplasmic changes which accompany the differentiation of spermatogonium into a mature sperm during spermatogenesis in the dragonfly (Aeschna sp.).The dragonfly spermatogonia are characterized by large round nuclei. Loosely organized chromatin is usually unevenly distributed within the spermatogonial nuclei. The scant cytoplasm surrounding the nucleus contains mitochondria, the Golgi apparatus, elements of endoplasmic reticulum and numerous ribosomes (Fig. 1).

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 THE MECHANISM OF A BROODING EFFECT ASSOCIATED WITH SEGREGATION DISTORTION IN DROSOPHILA MELANOGASTER

Genetics ◽  
1973 ◽  
Vol 74 (4) ◽  
pp. 619-631
Author(s):  
D L Hartl
Keyword(s):  
Drosophila Melanogaster ◽  
Segregation Distortion ◽  
Mature Sperm ◽  
Temperature Sensitive ◽  
Short Time

ABSTRACT The recovery of the SD chromosome from a heterozygous SD male increases with brood. This is independent of the age of the female, occurs during the time the sperm are stored in the females, disappears when the segregation distortion is suppressed, and is temperature-sensitive-temperature shocks above or below 25°C applied to the mature sperm both tend to accelerate the increase in the recovery of SD. All this suggests the existence of a class of sperm affected by SD in which the sperm are able to fertilize eggs for a short time following ejaculation but become dysfunctional thereafter.

scholarly journals The polymerization of actin: II. how nonfilamentous actin becomes nonrandomly distributed in sperm: evidence for the association of this actin with membranes

1976 ◽  
Vol 69 (1) ◽  
pp. 51-72 ◽  
Author(s):  
LG Tilney
Keyword(s):  
Plasma Membrane ◽  
Nuclear Envelope ◽  
Thin Section ◽  
Actin Filaments ◽  
Early Stage ◽  
Mature Sperm ◽  
Vacuole Membrane ◽  
Other Substances ◽  
Associated Proteins ◽  
Basal Half

At an early stage in spermiogenesis the acrosomal vacuole and other organelles including ribosomes are located at the basal end of the cell. From here actin must be transported to its future location at the anterior end of the cell. At no stage in the accumulation of actin in the periacrosomal region is the actin sequestered in a membrane-bounded compartment such as a vacuole or vesicle. Since filaments are not present in the periacrosomal region during the accumulation of the actin even though the fixation of these cells is sufficiently good to distinguish actin filaments in thin section, the actin must accumulate in the nonfilamentous state. The membranes in the periacrosomal region, specifically a portion of the nuclear envelope and the basal half of the acrosomal vacuole membrane, become specialized morphologically in advance of the accumulation of actin in this region. My working hypothesis is that the actin in combination with other substances binds to these specialized membranes and to itself and thus can accumulate in the periacrosmoal region by being trapped on these specialized membranes. Diffusion would then be sufficient to move these substances to this region. In support of this hypothesis are experiments in which I treated mature sperm with detergents, glycols, and hypotonic media, which solubilize or lift away the plasma membrane. The actin and its associated proteins remain attached to these specialized membranes. Thus actin can be nonrandomly distributed in cells in a nonfilamentous state presumably by its association with specialized membranes.

The likelihood of finding mature sperm cells in men with AZFb or AZFb-c deletions: six new cases and a review of the literature (1994–2010)

2011 ◽  
Vol 95 (6) ◽  
pp. 2005-2012.e4 ◽  
Author(s):  
Sandra E. Kleiman ◽  
Leah Yogev ◽  
Ofer Lehavi ◽  
Ron Hauser ◽  
Amnon Botchan ◽  
...  
Keyword(s):  
Mature Sperm ◽  
Sperm Cells ◽  
Review Of The Literature

scholarly journals The Effect of Testis Hormone on the Preservation of Sperm Life in the Vas Deferens of the Fowl

1938 ◽  
Vol 15 (2) ◽  
pp. 186-196
Author(s):  
S. S. MUNRO
Keyword(s):  
Natural Selection ◽  
Vas Deferens ◽  
Physiological Saline ◽  
Testicular Tissue ◽  
Sexual Cycle ◽  
Mature Sperm ◽  
Average Period ◽  
Ductus Deferens ◽  
Fertilizing Ability ◽  
Positive Effect

1. Mature sperm in the isolated ductus deferens of the fowl retain the capacity for movement in physiological saline for an average period of 26 or 28 days and a maximum of slightly more than 30 days, irrespective of the presence or absence of functional testicular tissue. Considering that sperm lose fertilizing ability before motility, this time accords closely with the reported survival of fertility in the hen after segregation from the cock. 2. While thus showing that testis hormone is not directly concerned with the maintenance of sperm life in the excurrent reproductive ducts of the fowl and suggesting that its positive effect in mammals is likewise indirect, it does not preclude the possibility that its action is expressed indirectly only through the epididymis. 3. The fact that the epididymis in the fowl is rather a vestigial organ and does not act as a storehouse for sperm makes it clear that in any case a physiologically controlled sperm-preserving mechanism plays no important role in the economy of reproduction in the fowl. 4. It is suggested that the nature of the demands made upon the supply of sperm in ducts of the males, as a consequence of the evolution of the sexual cycle in their respective females, satisfactorily accounts for the wide divergence in degree of epididymal development between Aves and Mammalia. Such demands, if in fact responsible for the divergence, have probably conferred advantages on well-equipped males and have most likely been produced through the agency of natural selection.

scholarly journals Intergenerational metabolic priming by sperm piRNAs

2021 ◽  
Author(s):  
Adelheid Lempradl ◽  
Unn Kugelberg ◽  
Mary Iconomou ◽  
Ian Beddows ◽  
Daniel Nätt ◽  
...  
Keyword(s):  
Small Rna ◽  
Small Rnas ◽  
Target Gene ◽  
Epigenetic Inheritance ◽  
Mature Sperm ◽  
Transcriptional Reprogramming ◽  
Complementary Sequences ◽  
Specific Manner ◽  
Dietary Sugar ◽  
Pirna Pathway

Preconception parental environment can reproducibly program offspring phenotype without altering the DNA sequence, yet the mechanisms underpinning this epigenetic inheritance remains elusive. Here, we demonstrate the existence of an intact piRNA-pathway in mature Drosophila sperm and show that pathway modulation alters offspring gene transcription in a sequence-specific manner. We map a dynamic small RNA content in developing sperm and find that the mature sperm carry a highly distinct small RNA cargo. By biochemical pulldown, we identify a small RNA subset bound directly to piwi protein. And, we show that piRNA-pathway controlled sperm small RNAs are linked to target gene repression in offspring. Critically, we find that full piRNA-pathway dosage is necessary for the intergenerational metabolic and transcriptional reprogramming events triggered by high paternal dietary sugar. These data provide a direct link between regulation of endogenous mature sperm small RNAs and transcriptional programming of complementary sequences in offspring. Thus, we identify a novel mediator of paternal intergenerational epigenetic inheritance.

scholarly journals Sperm ultrastructure of Pochazia shantungensis (Chou & Lu) and Ricania speculum (Walker) (Hemiptera, Ricaniidae) with phylogenetic implications

ZooKeys ◽  
2019 ◽  
Vol 880 ◽  
pp. 43-59
Author(s):  
Zhen Jiang ◽  
Jianing Liu ◽  
Daozheng Qin
Keyword(s):  
Neck Region ◽  
Mature Spermatozoon ◽  
Current Evidence ◽  
Sperm Ultrastructure ◽  
Transmission Electron ◽  
Phylogenetic Implications ◽  
Dense Substance ◽  
The Individual ◽  
Relationship Of ◽  
Centriole Adjunct

The sperm ultrastructure of two ricaniid species, Pochazia shantungensis (Chou &amp; Lu) and Ricania speculum (Walker), was investigated using light and transmission electron microscopy. Both species have monoflagellate sperm, the shape and ultrastructure of the mature spermatozoon of these two species are similar in morphology, and 128 spermatozoa are organized into sperm bundles with their heads embedded in a homogenous matrix forming the spermatodesmata. The individual sperm is filiform and includes the head, neck and flagellum. The head is needle-like, with a bilayer acrosome and an inferior elongated nucleus which is formed of homogeneously compact and electron-dense chromatin. The neck region is indistinct and is comprised of the centriole and centriole adjunct with a homogeneous dense substance. The long flagellum has the typical 9 + 9 + 2 axoneme microtubule pattern and two symmetrical mitochondrial derivatives with an orderly array of cristae flanking both sides, and a pair of well-developed fishhook-shaped accessory bodies. Current evidence shows that ricaniid species have D-shaped mitochondrial derivatives in cross-section and a serrated electron-dense region. The phylogenetic relationship of Fulgoroidea with other superfamilies in Auchenorrhyncha is briefly discussed.

Coiling of the Flagellar Shaft in the Head Region of the Mature Sperm of Nucella (Purpura) Lapillus (L.)

1969 ◽  
Vol 5 (1) ◽  
pp. 211-225
Author(s):  
MURIEL WALKER
Keyword(s):  
Sea Water ◽  
Nuclear Material ◽  
Sperm Nucleus ◽  
Mature Sperm ◽  
Langmuir Trough ◽  
Head Region ◽  
Anterior Portion ◽  
Normal Concentration ◽  
Ph Range ◽  
Dry Out

The sperm of Nucella are long and threadlike. The flagellar shaft runs from the acrosome at the front of the head to the tip of the tail. Its anterior portion, the head shaft, is ensheathed by the nucleus. If a suspension of sperm in normal-concentration sea water is observed under phase contrast, and allowed to dry out slowly, the nuclear material of sperm near the edge of the coverglass swells and the head shafts of these sperm are thrown into gentle spirals within the nuclei. In some sperm the nuclear material disperses completely, and the front threequarters of the head shaft springs into a tight right-handed coil of 5-7 turns. Instantaneous coiling of the head shaft may also be induced by treatment of the sperm with x 2 concentrated sea water or 0.01 % (w/v) solution of sodium lauryl sulphate in sea water. The enzymes pronase and trypsin at a concentration of 50µg/ml in sea water at pH 8.0 cause dispersion of the head nucleoprotein and subsequently the head shaft forms a loose coil. The appearance and activity of the sperm do not change perceptibly over a pH range of 5.5-8.5. Sperm spread on a Langmuir trough containing normal concentration sea water were negatively stained with phosphotungstic acid and examined with an electron microscope. After such treatment the nuclei are partially spread and the fibrils of the head shafts appear twisted as the wires of an electrical flex. The twisted flagellar fibrils are seen more clearly in negatively stained head shafts of sperm whose nuclei have been completely dispersed by spreading on a Langmuir trough containing x2 concentrated sea water. Negatively stained preparations of sperm treated with enzymes show sperm with twisted and coiled head shafts. The nucleoprotein of these sperm is disaggregated into strips or sheets, or may appear as a mass of branching fibres. The flagellar fibres of the enzyme-treated sperm are often bent or broken. Longitudinal sections of mature sperm heads show that in the intact sperm the fibres of the head shaft are not twisted but run straight throughout the length of the head. Sections from the testis and testicular duct show that microtubules are present in sperm in the testis but absent from mature sperm in the testicular duct. It is suggested that the head shaft, as a consequence of some event in spermiogenesis, has an inherent tendency to twist and coil but in the mature sperm it is ‘strait-jacketed’ by the sperm nucleus.

Sign in / Sign up

Export Citation Format

Share Document