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Histoarchitecture of the ovary of Rhipicephalus (Boophilus) annulatus during pre- and postengorgement period.

Kanapadinchareveetil S, Chandrasekhar L, Gopi J, Lenka DR, Vasu A, KGopalan AK, Nair SN, Ravindran R, Juliet S, Ghosh S - ScientificWorldJournal (2015)

Bottom Line: All the stages (II, III, IV, and V) of oocytes except stage I were similar to R. (B.) microplus.The stage I oocytes showed basophilia, which was not reported earlier in other species of ticks.Day wise changes were in the form of presence of oogonia in partially fed and day one engorged adults, considerable degeneration of oocytes on day two, emergence of new wave of oocytes on day three, presence of mature oocytes up to day eight, and complete degeneration of ovarian tissue from day eight onwards.

View Article: PubMed Central - PubMed

Affiliation: Department of Veterinary Pharmacology and Toxicology, College of Veterinary and Animal Sciences, Pookode, Wayanad, Kerala 673 576, India.

ABSTRACT
The present communication describes the detailed day wise study of histological changes of the ovary of Rhipicephalus (Boophilus) annulatus in the postengorgement period together with the systematic classification of their oocytes. The ovary of R. (B.) annulatus is panoistic type with an asynchronous development of oocytes. All the stages (II, III, IV, and V) of oocytes except stage I were similar to R. (B.) microplus. The stage I oocytes showed basophilia, which was not reported earlier in other species of ticks. Day wise changes were in the form of presence of oogonia in partially fed and day one engorged adults, considerable degeneration of oocytes on day two, emergence of new wave of oocytes on day three, presence of mature oocytes up to day eight, and complete degeneration of ovarian tissue from day eight onwards. The degenerative changes in the ovary appeared initially in the oocytes followed by germinal epithelium.

No MeSH data available.


Related in: MedlinePlus

Histological details of day wise changes. (a) Partially fed tick oogonia interconnected among themselves. (b) Vacuole inside oocyte. (c) Polymorphic oocytes. (d) Vacuolations in the nucleolus of germ vesicle. (e) Oocyte with amorphous material. (f) Oocyte fused to form a homogenous mass with series of germ vesicle inside. Og: spindle shaped oogonia; V: vacuole. Bars: (a), (d) 100x, (b), (c), (e), (f) 20x.
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fig2: Histological details of day wise changes. (a) Partially fed tick oogonia interconnected among themselves. (b) Vacuole inside oocyte. (c) Polymorphic oocytes. (d) Vacuolations in the nucleolus of germ vesicle. (e) Oocyte with amorphous material. (f) Oocyte fused to form a homogenous mass with series of germ vesicle inside. Og: spindle shaped oogonia; V: vacuole. Bars: (a), (d) 100x, (b), (c), (e), (f) 20x.

Mentions: Ovary of partially fed R. (B.) annulatus tick represented a picture of dense eosinophilic oogonia interconnected among themselves (Figure 2(a)). Oocytes were not differentiated at this stage. Germinal epithelium was observed at a small locus towards one pole. Nurse cells were not seen. However, in the ovary of partially fed Dermacentor andersoni, dense eosinophilic oogonia with intercellular bridges were previously described [23, 24]. In panoistic type ovaries, oogonia directly give rise to oocytes without nurse cells [25]. In the present study, oogonia were observed in both partially fed and fully engorged ticks (up to day one after engorgement). However, oogonia were not observed in semiengorged A. triste [8]. Observation of the tick's ovary on the day of complete engorgement revealed a similar picture as that of partially fed stage. Oogonia were clearly distinguished as spindle shaped masses having cord-like connections radiating from two or more different sites. The cords gave attachment to large number of small refractile bodies. These refractile bodies could be lipid droplets incorporated into the oocytes after a blood meal. In insects, the digested blood containing a large amount of lipids is secreted to the hemolymph and taken up by the growing oocytes for producing molecules such as vitellogenins [26]. Germinal epithelial cells were more in number in the engorged ticks compared to the partially fed. The nuclear to cytoplasmic ratio of epithelial cells was high. Appearance of dense eosinophilic oogonia and absence of nurse cells strongly suggested that ovary of R. (B.) annulatus is of panoistic type.


Histoarchitecture of the ovary of Rhipicephalus (Boophilus) annulatus during pre- and postengorgement period.

Kanapadinchareveetil S, Chandrasekhar L, Gopi J, Lenka DR, Vasu A, KGopalan AK, Nair SN, Ravindran R, Juliet S, Ghosh S - ScientificWorldJournal (2015)

Histological details of day wise changes. (a) Partially fed tick oogonia interconnected among themselves. (b) Vacuole inside oocyte. (c) Polymorphic oocytes. (d) Vacuolations in the nucleolus of germ vesicle. (e) Oocyte with amorphous material. (f) Oocyte fused to form a homogenous mass with series of germ vesicle inside. Og: spindle shaped oogonia; V: vacuole. Bars: (a), (d) 100x, (b), (c), (e), (f) 20x.
© Copyright Policy - open-access
Related In: Results  -  Collection

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fig2: Histological details of day wise changes. (a) Partially fed tick oogonia interconnected among themselves. (b) Vacuole inside oocyte. (c) Polymorphic oocytes. (d) Vacuolations in the nucleolus of germ vesicle. (e) Oocyte with amorphous material. (f) Oocyte fused to form a homogenous mass with series of germ vesicle inside. Og: spindle shaped oogonia; V: vacuole. Bars: (a), (d) 100x, (b), (c), (e), (f) 20x.
Mentions: Ovary of partially fed R. (B.) annulatus tick represented a picture of dense eosinophilic oogonia interconnected among themselves (Figure 2(a)). Oocytes were not differentiated at this stage. Germinal epithelium was observed at a small locus towards one pole. Nurse cells were not seen. However, in the ovary of partially fed Dermacentor andersoni, dense eosinophilic oogonia with intercellular bridges were previously described [23, 24]. In panoistic type ovaries, oogonia directly give rise to oocytes without nurse cells [25]. In the present study, oogonia were observed in both partially fed and fully engorged ticks (up to day one after engorgement). However, oogonia were not observed in semiengorged A. triste [8]. Observation of the tick's ovary on the day of complete engorgement revealed a similar picture as that of partially fed stage. Oogonia were clearly distinguished as spindle shaped masses having cord-like connections radiating from two or more different sites. The cords gave attachment to large number of small refractile bodies. These refractile bodies could be lipid droplets incorporated into the oocytes after a blood meal. In insects, the digested blood containing a large amount of lipids is secreted to the hemolymph and taken up by the growing oocytes for producing molecules such as vitellogenins [26]. Germinal epithelial cells were more in number in the engorged ticks compared to the partially fed. The nuclear to cytoplasmic ratio of epithelial cells was high. Appearance of dense eosinophilic oogonia and absence of nurse cells strongly suggested that ovary of R. (B.) annulatus is of panoistic type.

Bottom Line: All the stages (II, III, IV, and V) of oocytes except stage I were similar to R. (B.) microplus.The stage I oocytes showed basophilia, which was not reported earlier in other species of ticks.Day wise changes were in the form of presence of oogonia in partially fed and day one engorged adults, considerable degeneration of oocytes on day two, emergence of new wave of oocytes on day three, presence of mature oocytes up to day eight, and complete degeneration of ovarian tissue from day eight onwards.

View Article: PubMed Central - PubMed

Affiliation: Department of Veterinary Pharmacology and Toxicology, College of Veterinary and Animal Sciences, Pookode, Wayanad, Kerala 673 576, India.

ABSTRACT
The present communication describes the detailed day wise study of histological changes of the ovary of Rhipicephalus (Boophilus) annulatus in the postengorgement period together with the systematic classification of their oocytes. The ovary of R. (B.) annulatus is panoistic type with an asynchronous development of oocytes. All the stages (II, III, IV, and V) of oocytes except stage I were similar to R. (B.) microplus. The stage I oocytes showed basophilia, which was not reported earlier in other species of ticks. Day wise changes were in the form of presence of oogonia in partially fed and day one engorged adults, considerable degeneration of oocytes on day two, emergence of new wave of oocytes on day three, presence of mature oocytes up to day eight, and complete degeneration of ovarian tissue from day eight onwards. The degenerative changes in the ovary appeared initially in the oocytes followed by germinal epithelium.

No MeSH data available.


Related in: MedlinePlus