Reproductive Traits of an Invasive Alien Population of Grey Squirrel (Sciurus carolinensis) in Central Italy
<p>(<b>a</b>) An ovary with a corpus luteum (arrow) on the surface. (<b>b</b>) A reproductive apparatus, after cutting the broad ligament and stretching, composed of the ovaries and fallopian tubes (arrows), uterine horns (arrowhead), and vulva (v); two uterine horns placed side by side in their distal end (bold arrow). The broad ligament infiltrated by adipose bodies (*) can be observed. The dashed line indicates that the length of the uterus was measured between the two proximal ends. (<b>c</b>) A white, small, ribbon-like and quite relaxed uterus belonging to an immature squirrel. (<b>d</b>) Two embryonic vesicles (arrows) are contained within a uterus strongly folded back on itself and forming spiral loops. Bladder (*) and vulva (v) are shown. (<b>e</b>) Dorsal surface with a transverse groove (arrow) defining the border between the cervix and the vagina. The bladder (*) can be observed below the vagina. (<b>f</b>) Distal and medial portion of the two uterine horns opened to show longitudinal folds of the mucosa. The arrows indicate the two external orifices of the uterus.</p> "> Figure 2
<p>A uterus after the treatment to evidence uterine scars. The arrows highlight more recent darker scars, while the arrowheads indicate older, lighter-coloured scars.</p> "> Figure 3
<p>Testicles belonging to squirrels of different ages and breeding status.</p> "> Figure 4
<p>Images of testicles in different reproductive phases. (<b>a</b>) Immature phase: germinal epithelium where tubules are small and devoid of lumen; the epithelium consists of numerous Sertoli cells located at the base and some spermatogonia with abundant cytoplasm in a more central position. (<b>b</b>) Pubertal phase: some tubules have large lumen and the epithelium consists mainly of basal Sertoli cells and primary spermatocytes in the luminal compartment; round spermatids and a cluster of Leydig cells can also be observed. (<b>c</b>) Spermatogenesis phase: all tubules show a large lumen; epithelium is completely formed and is in active spermatogenesis with elongated spermatids. (<b>d</b>) Regression phase: testicles with degenerated germinal cells occupying the lumen.</p> "> Figure 5
<p>Images of epididymis in different reproductive phases. (<b>a</b>) Immature phase: the diameter of the epididymis is small and the lumen is empty. (<b>b</b>) Spermatogenesis phase: the diameter of the epididymis is larger and it is full of spermatozoa. (<b>c</b>) Regressive phase: cell debris and squamous cells can be observed in the epididymis lumen.</p> ">
Abstract
:Simple Summary
Abstract
1. Introduction
2. Materials and Methods
2.1. Animal Capture and Sample Collection
2.2. Morphometric Evaluation of the Female Genital System and Uterine Scar Analysis
2.3. Morphometric Evaluation of the Testicles
2.4. Statistical Analysis
3. Results
3.1. Morphometric Evaluation of the Female Genital System
3.2. Uterine Scar Analysis
3.3. Morphometric and Histological Evaluation of the Testicles
4. Discussion
5. Conclusions
Author Contributions
Funding
Acknowledgments
Conflicts of Interest
References
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Reproductive Phase | Body Weight (g) | Ovary Status | Ovary Weight (mg) | Ovary Length (cm) | Ovary Width (cm) | Uterus Appearance | Uterus Weight (g) | Uterine Scar | Uterine Horn Length (cm) | Uterine Horn Width (cm) | Uterine Body Length (cm) | Uterine Body Width (cm) |
---|---|---|---|---|---|---|---|---|---|---|---|---|
Immature | 438.01 a ± 43.24 | No graafian follicle | 0.24 a ± 0.21 | 0.37 a ± 0.10 | 0.24 a,b ± 0.06 | Small, ribbon-like | 0.22 a ± 0.08 | No | 6.4 a ± 1.8 | 0.20 a ± 0.4 | 0.76 a,b,c ± 0.31 | 0.41 a,b,c ± 0.18 |
Follicular | 521.54 a,b ± 55.5 | Graafian follicle | 0.23 a ± 0.04 | 0.38 a ± 0.06 | 0.27 a,b ± 0.05 | Round, oedematous, tonic in the oestrous phase | 0.82 a ± 0.49 | Yes/No | 9.6 b ± 3.1 | 0.35 b ± 0.11 | 1.01 a,b,c ± 0.38 | 0.64 a,b,c ± 0.16 |
Luteal | 562.99 b ± 19.49 | Corpus luteum | 0.64 a ± 0.48 | 0.49 a ± 0.19 | 0.36 b.c ± 0.19 | Round, oedematous, tonic | 2.08 b ± 0.53 | Yes/No | 13.3 c ± 2.8 | 0.46 c ± 0.08 | 1.24 a,b,c ± 0.29 | 0.76 b ± 0.15 |
Pregnant | 550.02 b ± 11.55 | Corpus luteum in the first period | 0.21 a ± 0.05 | 0.42 a ± 0.06 | 0.32 b,c ± 0.03 | Round, oedematous, tonic, with embryonic vesicles/embryos/foetuses | 3.28 b ± 1.05 | No | 15.5 c ± 3.9 | 0.51 c ± 0.13 | 1.45 b ± 0.33 | 0.98 b ± 0.40 |
Anoestrous | 495.38 a,b ± 57.99 | No graafian follicle | 0.33 a ± 0.20 | 0.39 a ± 0.07 | 0.26 a,b ± 0.05 | Small, ribbon-like | 0.57 a ± 0.30 | Yes/No | 9.4 b ± 2.2 | 0.34 b ± 0.08 | 0.96 c ± 0.26 | 0.56 c ± 0.09 |
Reproductive Phase | ||||||
---|---|---|---|---|---|---|
Catch period | Immature | Follicular | Luteal | Pregnant | Anoestrus | Total |
Winter 15/12–15/03 | 1 | 4 | 6 | 7 | 4 | 21 |
Spring 15/03–15/06 | 1 | 9 | 6 | 2 | 6 | 24 |
Summer 15/06–15/09 | 1 | - | - | 1 | - | 2 |
Autumn 15/09–15/12 | 2 | - | - | - | 14 | 16 |
Total | 5 (7.81%) | 13 (20.31%) | 12 (18.75%) | 10 (15.65%) | 24 (37.5%) | 63 |
Litter Presence | No. of Females | Litter Size | ||
---|---|---|---|---|
None | 14 (31%) | Period | Number of scars/female | Uterine scars range |
One | 17 (38%) | 15/12–15/03 | 3.55 ± 1.88 * | 1−7 |
Two | 14 (31%) | 16/03–15/06 | 2.14 ± 1.46 | 2−6 |
Total | 45 | Annual | 4.52 ± 1.88 | 1−7 |
Reproductive Phase | Body Weight (gr) | Testicle Weight (gr) | Testicle Length (cm) | Testicle Width (cm) | Epididymis Weight (gr) | ST Diameter (µm) | Testicle Position | Germinative Epithelium Morphotype | SG |
---|---|---|---|---|---|---|---|---|---|
Immature | 399.25 a ± 70.11 | 0.10 a ± 0.03 | 0.84 a ± 0.23 | 0.44 a ± 0.15 | 0.19 a ± 0.16 | 79.93 a ± 18.70 | ABD | Mp1 | No |
Pubertal | 460.18 a,b ± 43.67 | 0.69 b ± 0.29 | 1.82 b ± 0.18 | 0.88 b ± 0.17 | 0.85 b ± 0.60 | 151.49 b ± 20.05 | SCR | Mp2 | No |
Spermatogenesis | 502.31 b ± 46.37 | 2.52 c ± 0.26 | 2.00 b ± 0.46 | 1.34 c ± 0.46 | 2.01 c ± 0.62 | 241.18 c ± 26.38 | SCR | Mp3 | Yes |
Regression | 515.40 b ± 36.11 | 1.85 d ± 0.17 | 2.01 b ± 0.22 | 1.11 b,c ± 0.16 | 0.36 a,b ± 0.22 | 166.52 b ± 55.35 | SCR | Mp4 | No |
Reproductive Phase | |||||
---|---|---|---|---|---|
Immature | Pubertal | Spermatogenesis | Regression | Total N | |
Winter 15/12–15/03 | 4 | 9 | 10 | 3 | 26 |
Spring 15/03–15/06 | 5 | 1 | 6 | ||
Summer 15/06–15/09 | 5 | 2 | 7 | ||
Autumn 15/09–15/12 | 7 | 2 | 2 | 1 | 12 |
Total | 16 (31.37%) | 11 (21.57%) | 19 (37.26%) | 5 (9.80%) | 51 |
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Maranesi, M.; Bufalari, A.; Dall’Aglio, C.; Paoloni, D.; Moretti, G.; Crotti, S.; Manuali, E.; Stazi, M.; Bergamasco, F.; Cruciani, D.; et al. Reproductive Traits of an Invasive Alien Population of Grey Squirrel (Sciurus carolinensis) in Central Italy. Animals 2020, 10, 738. https://doi.org/10.3390/ani10040738
Maranesi M, Bufalari A, Dall’Aglio C, Paoloni D, Moretti G, Crotti S, Manuali E, Stazi M, Bergamasco F, Cruciani D, et al. Reproductive Traits of an Invasive Alien Population of Grey Squirrel (Sciurus carolinensis) in Central Italy. Animals. 2020; 10(4):738. https://doi.org/10.3390/ani10040738
Chicago/Turabian StyleMaranesi, Margherita, Antonello Bufalari, Cecilia Dall’Aglio, Daniele Paoloni, Giulia Moretti, Silvia Crotti, Elisabetta Manuali, Marica Stazi, Francesca Bergamasco, Deborah Cruciani, and et al. 2020. "Reproductive Traits of an Invasive Alien Population of Grey Squirrel (Sciurus carolinensis) in Central Italy" Animals 10, no. 4: 738. https://doi.org/10.3390/ani10040738