Sperm-cell ultrastructure of North American sturgeons. IV. The pallid sturgeon (Scaphirhynchus albus Forbes and Richardson, 1905)

2001 ◽  
Vol 79 (5) ◽  
pp. 802-808 ◽  
Author(s):  
Martin N DiLauro ◽  
Rosemary A Walsh ◽  
Michelle Peiffer ◽  
Randy M Bennett
Keyword(s):  
Sperm Cell ◽  
Longitudinal Axis ◽  
Cell Ultrastructure ◽  
Sperm Cells ◽  
Atlantic Sturgeon ◽  
Ultrastructural Studies ◽  
Pallid Sturgeon ◽  
Oak Tree ◽  
Distal Centriole ◽  
Scaphirhynchus Albus

Sperm-cell morphology and ultrastructure in the pallid sturgeon (Scaphirhynchus albus) were examined using transmission and scanning electron microscopy. Metrics and structure were compared with similar metrics obtained from other published descriptions of sturgeon sperm cells. General morphology was found to be similar to that of sperm cells of the white (Acipenser transmontanus), lake (A. fulvescens), stellate (A. stellatus), Chinese (A. sinensis), Russian (A. gueldenstaedti colchicus), and shortnose (A. brevirostrum) sturgeons, which all shared a gradual tapering of the nuclear diameter from posterior to anterior, unlike that of the Atlantic sturgeon (A. oxyrhynchus). The sperm cell of the pallid sturgeon was similar in size to that of the Atlantic sturgeon, being only slightly larger. The sperm cell of the pallid sturgeon differed from those of other sturgeons chiefly in the acrosomal region, where the posterolateral projections (PLP) have the shape of an acute triangle and are arranged in a spiral about the longitudinal axis of the cell. The PLP were longer than those of other sturgeons, being twice the length of those of the Atlantic sturgeon and 58% longer than those of the lake sturgeon. Also, in cross section the acrosome had the shape of a hollow cone rather than the cap of an oak tree acorn, as was found in ultrastructural studies of other sturgeons. In addition, we were able to confirm that the structural arrangement of the distal centriole of the midpiece is identical with that of the proximal centriole: nine sets of microtubular triplets around the periphery of the centriole. This information is of potential use to fishery biologists, forensic biologists, zoologists, reproductive physiologists, taxonomists, evolutionary biologists, and aquaculturists.

Sperm-cell ultrastructure of North American sturgeons. IV. The pallid sturgeon (Scaphirhynchus albus Forbes and Richardson, 1905)

2001 ◽  
Vol 79 (5) ◽  
pp. 802-808 ◽  
Author(s):  
Martin N. DiLauro ◽  
Rosemary A. Walsh ◽  
Michelle Peiffer ◽  
Randy M. Bennett
Keyword(s):  
North American ◽  
Sperm Cell ◽  
Cell Ultrastructure ◽  
Pallid Sturgeon ◽  
Scaphirhynchus Albus

Sperm-cell ultrastructure of North American sturgeons. II. The shortnose sturgeon (Acipenser brevirostrum, Lesueur, 1818)

1999 ◽  
Vol 77 (2) ◽  
pp. 321-330 ◽  
Author(s):  
Martin N DiLauro ◽  
Wayne S Kaboord ◽  
Rosemary A Walsh
Keyword(s):  
Sperm Cell ◽  
Cell Ultrastructure ◽  
Sperm Cells ◽  
Shortnose Sturgeon ◽  
Atlantic Sturgeon ◽  
Head Region ◽  
Acipenser Brevirostrum ◽  
Transmission Electron ◽  
Structural Connection ◽  
Single Flagellum

The fine structure of the sperm cell of the shortnose sturgeon (Acipenser brevirostrum) was examined using transmission electron microscopy and selected metrics. The cell possesses a distinct acrosome, a defined head region, a midpiece, and a single flagellum. The mean length of the sperm cell body (acrosome + nucleus + midpiece) is approximately 9.71 µm, and the length of the flagellum is about 37 µm, resulting in a total cell length of about 46 µm. The sperm cell of the shortnose sturgeon is much longer and slightly wider than that of the Atlantic sturgeon. The nuclei of shortnose, white, and stellate sturgeon sperm cells are elongate trapezoids with the anterior (acrosome) end narrowest, the opposite of that of the Atlantic sturgeon. Although slightly smaller in total length and width than the sperm cells of the stellate and white sturgeons, that of the shortnose sturgeon is most similar to them in overall ultrastructure, as all three cells have three endonuclear canals. A structural connection of unknown function between the nuclear fossa and the proximal centriole, which is similar to the fibrous body in other species, is present in the shortnose sturgeon sperm cell. Our results suggest a more recent evolutionary link between the shortnose, white, and stellate sturgeons than between any of these and the Atlantic sturgeon. This is the first description of sperm cell ultrastructure in the shortnose sturgeon, an endangered species.

Sperm-cell ultrastructure of North American sturgeons. I. The Atlantic sturgeon (Acipenser oxyrhynchus)

1998 ◽  
Vol 76 (10) ◽  
pp. 1822-1836 ◽  
Author(s):  
Martin N DiLauro ◽  
Wayne Kaboord ◽  
Rosemary A Walsh ◽  
William F Krise ◽  
Michael A Hendrix
Keyword(s):  
Electron Microscopy ◽  
Sperm Cell ◽  
Evolutionary Relationship ◽  
Lake Sturgeon ◽  
White Sturgeon ◽  
Evolutionary Relationships ◽  
Head Width ◽  
Sperm Cells ◽  
Atlantic Sturgeon ◽  
Stellate Sturgeon

Atlantic sturgeon (Acipenser oxyrhynchus) and lake sturgeon (Acipenser fulvescens) sperm-cell morphologies were examined using scanning electron microscopy. Major differences were found in four of nine metrics, all in the head region of the cell. Atlantic sturgeon sperm cells were much shorter than those of lake sturgeon. Anterior head width exceeded posterior head width, in contrast to the arrangement in lake sturgeon sperm cells. Lake sturgeon sperm cells are nearer in size to those of other sturgeons than are Atlantic sturgeon sperm cells. Comparisons were made with sperm-cell structures known from other sturgeon species, including the Russian sturgeon (Acipenser gueldenstaedti colchicus), stellate sturgeon (Acipenser stellatus), Chinese sturgeon (Acipenser sinensis), and white sturgeon (Acipenser transmontanus). Variation in cell morphology may indicate evolutionary relationships. In addition, the fine structure of Atlantic sturgeon sperm cells was examined using transmission electron microscopy and selected metrics are described. The cell possesses a distinct acrosome, a midpiece, and a single flagellum. A comparison is made with ultrastructural details of the sperm cells of stellate and white sturgeons. Similarities among these species include radial symmetry about the longitudinal axis, an elongate shape, a distinct acrosome, and the presence of endonuclear canals. Noteworthy differences include a smaller total length and width than stellate and white sturgeon sperm cells. The main sperm-cell body is approximately 4 µm long and the flagellum about 37 µm long, resulting in a total cell length of about 41 µm. Also, the Atlantic sturgeon sperm cell possesses only two membraned endonuclear canals, in contrast to the arrangement in white and stellate sturgeons, where three such organelles are found. A structural connection of unknown function between the nuclear fossa and proximal centriole is also present in the Atlantic sturgeon sperm cell. Sperm-cell nuclei of white and stellate sturgeons are elongate trapezoids, with the anterior end narrower, whereas in Atlantic sturgeon the anterior portion of the trapezoid is wider than the posterior. Structural similarities between species may indicate a commonality of ancestral and evolutionary relationships that may have taxonomic implications. Ultrastructure suggests a closer evolutionary relationship between the white and stellate sturgeon than between either of these species and the Atlantic sturgeon. The present findings may be used by biologists studying the reproductive physiology, forensics, taxonomy, and genetics of sturgeons.

Sperm-cell ultrastructure of North American sturgeons. I. The Atlantic sturgeon (Acipenser oxyrhynchus)

1998 ◽  
Vol 76 (10) ◽  
pp. 1822-1836 ◽  
Author(s):  
Martin N. DiLauro ◽  
Wayne Kaboord ◽  
Rosemary A. Walsh ◽  
William F. Krise ◽  
Michael A. Hendrix
Keyword(s):  
North American ◽  
Sperm Cell ◽  
Cell Ultrastructure ◽  
Atlantic Sturgeon

Sperm-cell ultrastructure of North American sturgeons. III. The lake sturgeon (Acipenser fulvescens Rafinesque, 1817)

2000 ◽  
Vol 78 (3) ◽  
pp. 438-447 ◽  
Author(s):  
Martin N DiLauro ◽  
Wayne S Kaboord ◽  
Rosemary A Walsh
Keyword(s):  
Sperm Cell ◽  
Radial Symmetry ◽  
Lake Sturgeon ◽  
Acipenser Fulvescens ◽  
Sperm Cells ◽  
Shortnose Sturgeon ◽  
Atlantic Sturgeon ◽  
Cell Nuclei ◽  
Head Region ◽  
Anterior Portion

Lake sturgeon (Acipenser fulvescens) sperm cell fine structure was examined using transmission electron microscopy. The cell possesses a distinct acrosome, a defined head region, a midpiece, and a single flagellum. Sperm cells of this species share a general radial symmetry, an elongate shape, a distinct acrosome, and the presence of endonuclear canals with those of other sturgeons. The mean length of the lake sturgeon sperm cell body (acrosome + nucleus + midpiece) is approximately 7.13 µm and the length of the flagellum is about 50 µm, resulting in a total cell length of about 57 µm. The lake sturgeon sperm cell is much longer and slightly wider than that of the Atlantic sturgeon. The sperm-cell nuclei of lake, shortnose, white, and stellate sturgeons are elongate trapezoids in shape, with the anterior (acrosome) end narrowest but, in the Atlantic sturgeon, the anterior portion of the trapezoid is wider than the posterior. Although slightly smaller in total length and width, the lake sturgeon sperm cell is most similar to the shortnose sperm cell in ultrastructure, overall size, and shape; it also shares similarity of shape with the stellate and white sturgeon sperm cells. The cell nuclei of these four sturgeons have three endonuclear canals. The acrosome of the lake sturgeon sperm cell has longer posterolateral projections than that of the Atlantic or shortnose sturgeon sperm cell. A structural connection, the fibrous body, is present in the lake sturgeon sperm cell between the nuclear fossa and the proximal centriole, as in the Atlantic and shortnose sturgeon sperm cells. Our results suggest a more recent evolutionary linkage between the lake and shortnose sturgeons than with the Atlantic sturgeon. This work presents the first ultrastructural description of the lake sturgeon sperm cell.

scholarly journals Persistent directional growth capability in Arabidopsis thaliana pollen tubes after nuclear elimination from the apex

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Kazuki Motomura ◽  
Hidenori Takeuchi ◽  
Michitaka Notaguchi ◽  
Haruna Tsuchi ◽  
Atsushi Takeda ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Pollen Tube ◽  
Sperm Cell ◽  
Pollen Tubes ◽  
Vegetative Nucleus ◽  
Sperm Cells ◽  
Apical Region ◽  
Basal Region ◽  
Specific Expression ◽  
Directional Growth

AbstractDuring the double fertilization process, pollen tubes deliver two sperm cells to an ovule containing the female gametes. In the pollen tube, the vegetative nucleus and sperm cells move together to the apical region where the vegetative nucleus is thought to play a crucial role in controlling the direction and growth of the pollen tube. Here, we report the generation of pollen tubes in Arabidopsis thaliana whose vegetative nucleus and sperm cells are isolated and sealed by callose plugs in the basal region due to apical transport defects induced by mutations in the WPP domain-interacting tail-anchored proteins (WITs) and sperm cell-specific expression of a dominant mutant of the CALLOSE SYNTHASE 3 protein. Through pollen-tube guidance assays, we show that the physiologically anuclear mutant pollen tubes maintain the ability to grow and enter ovules. Our findings provide insight into the sperm cell delivery mechanism and illustrate the independence of the tip-localized vegetative nucleus from directional growth control of the pollen tube.

scholarly journals Influence of Campylobacter fetus subsp. fetus on ram sperm cell quality

2008 ◽  
Vol 57 (11) ◽  
pp. 1405-1410 ◽  
Author(s):  
Tidhar Zan Bar ◽  
Ronen Yehuda ◽  
Tomer Hacham ◽  
Sigal Krupnik ◽  
Benjamin Bartoov
Keyword(s):  
Sperm Cell ◽  
Sperm Cells ◽  
Male Factor ◽  
Motility Index ◽  
Fas Receptor ◽  
Campylobacter Fetus ◽  
Fetus Subsp ◽  
Ram Sperm ◽  
Female Sheep

Campylobacter fetus subsp. fetus infection can occur in female sheep, causing infertility or abortion. Despite extensive research on the effect of these bacteria on female fertility, little research has been done on the influence of C. fetus subsp. fetus on the male factor. Our objective was to examine the influence of C. fetus subsp. fetus on ram sperm. Motility index, percentage of live spermatozoa, mean αt value (an indication of the chromatin stability of the sperm cell) and percentage of sperm cells expressing the FAS receptor were measured in sperm incubated in the presence or absence of C. fetus subsp. fetus. The motility index and viability of sperm incubated with the bacteria were lower than those of untreated sperm samples after 5 h. In bacteria-incubated sperm cells, the percentage expressing FAS receptor was already significantly elevated at 15 min. Bacteria-incubated sperm showed a greater prevalence of morphological damage. The bacteria were attached to tail and acrosome regions, and the sperm damage was concentrated in both the motility and chromatin regions. Bacteria-infected sperm cells showed a decrease in motility, increase in early acrosome reaction and chromatin damage. Similar effects were induced by incubation of the sperm with supernatants from C. fetus subsp. fetus cultures. Thus this study demonstrates that C. fetus subsp. fetus has a detrimental effect on the quality of ram sperm.

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