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Baso A, Bello UM, Sulaiman MH, Gosomji IJ, Omirinde OJ, Zubairu M, Abubakar MT. Photoperiodic-dependent histomorphological changes in the excurrent duct system of helmeted guinea fowl subjected to short day (8L:16D), long-day (16L:8D) light/dark cycles and exogenous melatonin. Vet Anim Sci 2022; 19:100282. [PMID: 36618853 PMCID: PMC9811253 DOI: 10.1016/j.vas.2022.100282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
In the present study, the influence of varying photoperiods [short day light 8L:16D, long day light 16L;8D] and exogeneous melatonin on the excurrent duct system of male helmeted guinea fowl was investigated using histo-morphological and histometric approaches. A total of twenty-eight (28) guinea fowl birds were randomly divided into Group I: Short daylight (SD; 8 HL), Group II: (SD +1mg/kg melatonin; 8 HL+ Mel), Group III: Long daylight (LD; 16 HL) and Group IV: (LD +1mg/kg; 16 HL + Mel)] and comprises of seven birds (n=7) per group. At the end of the 8 weeks of experimentation, the excurrent ducts were excised and processed for routine histological examination and the variations in histo-morphometrical parameters were determined using the GIMP2 software. Histologically, apart from the moderate cellular degeneration observed in efferent duct epithelia of the SD subgroups: (8 HL and 8 HL + Mel), there was remarkable spermatozoa presence in the lumens of the epididymal duct and ductus deferens of both 16 HL and 16 HL + Mel groups. The histo-morphometric data (luminal, ductal diameters and epithelial heights) were significantly increased (p <0.05) in the excurrent ducts of guinea fowl exposed to 16 HL and 16 HL + Mel, as compared to other groups. There was significant decrease (p <0.05) in stereocilia height (SH) in 16 HL compared to 8 HL sub-groups of lower segments. Although, a non-significant (p >0.05) increase in SH was observed in melatonin-treated groups, regardless of photoperiod. Taken together, these sets of data from this study indicate the importance of artificial light and exogenous melatonin in the control of seasonality of reproduction and which could be used to influence the reproductive cycle of the guinea fowl.
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Affiliation(s)
- Abdullahi Baso
- Laboratory of Cell Biology and Histology, Department of Veterinary Anatomy, Faculty of Veterinary Medicine, Ahmadu Bello University, Zaria, Nigeria,Department of Veterinary Anatomy, Faculty of Veterinary Medicine, Bayero University, Kano, Nigeria
| | - Umar M. Bello
- Laboratory of Cell Biology and Histology, Department of Veterinary Anatomy, Faculty of Veterinary Medicine, Ahmadu Bello University, Zaria, Nigeria,Corresponding author.
| | - Mohammed H. Sulaiman
- Laboratory of Cell Biology and Histology, Department of Veterinary Anatomy, Faculty of Veterinary Medicine, Ahmadu Bello University, Zaria, Nigeria
| | - Innocent J. Gosomji
- Laboratory of Cell Biology and Histology, Department of Veterinary Anatomy, Faculty of Veterinary Medicine, Ahmadu Bello University, Zaria, Nigeria,Department of Veterinary Anatomy, Faculty of Veterinary Medicine, University of Jos, Nigeria
| | - Oyewole J. Omirinde
- Department of Veterinary Anatomy, Faculty of Veterinary Medicine, University of Jos, Nigeria
| | - Mansur Zubairu
- Laboratory of Cell Biology and Histology, Department of Veterinary Anatomy, Faculty of Veterinary Medicine, Ahmadu Bello University, Zaria, Nigeria
| | - Muazu. T. Abubakar
- Department of Veterinary Anatomy, Faculty of Veterinary Medicine, Bayero University, Kano, Nigeria
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Hypothalamic expression of GnRH-I and GnIH in the Eurasian tree sparrow over a single long day. Photochem Photobiol Sci 2022; 21:147-158. [PMID: 35037197 DOI: 10.1007/s43630-021-00143-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 11/17/2021] [Indexed: 10/19/2022]
Abstract
Seasonal reproductive cycles of most birds are regulated by photoperiod via neuroendocrine control. The present study aims to investigate the role of a single long day in triggering hypothalamic expressions of GnRH-I and GnIH in the Eurasian tree sparrow (Passer montanus). Sparrows were divided into two groups (n = 24 each) and pre-treated under short days (9L: 15D) for 4 days. On the fifth day, one group was exposed to long day (14L: 10D), while other was continued under short day for another 1 day. Birds of both the groups were sacrificed and perfused on fifth day at different time points, i.e., ZT 14, ZT 16 and ZT 18 and the expressions of GnRH-I and GnIH mRNAs and peptides were studied using real-time PCR and immunohistochemistry, respectively. In addition, testicular size was measured to know testicular development. Observations revealed that birds exposed to a single long day (14L: 10D) showed an increase in hypothalamic expressions of GnRH-I mRNA and peptide and decrease in levels of GnIH mRNA only at ZT 16 and ZT 18 with no significant change in GnIH peptide. However, no significant change in GnRH-I or GnIH expression was observed at any time point under short day and birds maintained high and low expression levels of GnIH and GnRH-I, respectively. Our results clearly indicate that the photoperiodic response system of sparrow is highly sensitive to light and responds even to single long day. Furthermore, they suggest that the GnRH-I and GnIH are expressed in the hypothalamus of tree sparrow in an anti-phasic manner and switching over of their expression occurs at late hours of exposure of birds to single long day.
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Singh NS, Dixit AS, Khanikar D. Morphological and Ultrastructural Studies of Pecten in the Eurasian Tree Sparrow. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2021; 27:1-9. [PMID: 34657649 DOI: 10.1017/s1431927621012885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
We studied the fine histological structures of pecten oculi of the Eurasian tree sparrow using various microscopy techniques. The pecten of the tree sparrow was found to be of a pleated type comprising of pleats, bridges, and base. The light microscopic study revealed further that the pleats consist of capillaries of varying sizes, blood vessels, and numerous pigmented cells that give them a black color. Histochemical studies of pecten showed a large deposition of lipid droplets, which were more abundant in the basal area. The transmission electron microscopy displayed capillaries and blood vessels that remain surrounded by a thick fibrous basal membrane. They are formed of endothelial cells having a large lumen and abluminal area with microfolds. Interstitial spaces were found filled with rounded melanocytes, electron-dense pigment granules, and mitochondria. Observations under the scanning electron microscope revealed the presence of a dense vascular network of capillaries and vessels. In addition, large hyalocytes were also observed on the surface of the pleats. The above observations suggest that the histological structure of the pecten of the tree sparrow resembles those present in the pecten of other diurnal birds. However, further investigation is required to ascertain its functional role in birds.
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Affiliation(s)
- Namram S Singh
- Department of Zoology, Cotton University, Guwahati, 781001, Assam, India
| | - Anand S Dixit
- Department of Zoology, North-Eastern Hill University, Shillong, 793022, Meghalaya, India
| | - Debashish Khanikar
- Department of Zoology, North-Eastern Hill University, Shillong, 793022, Meghalaya, India
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Renthlei Z, Borah BK, Trivedi AK. Urban environment alter the timing of progression of testicular recrudescence in tree sparrow (Passer montanus). ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:31097-31107. [PMID: 33595800 DOI: 10.1007/s11356-021-12918-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 02/08/2021] [Indexed: 06/12/2023]
Abstract
Urbanization is a rapidly growing phenomenon that affects wildlife. Laboratory studies show the effects of night light on the physiology of the organisms. Limited studies have been conducted on birds in their natural habitat. Here, we studied the effects of the urban environment on reproduction-linked phenomenon and molecules involved in the regulation of seasonal breeding. Birds (N=5/time/site) were procured from urban and rural sites at specific times, i.e., in March (stimulatory phase), June (reproductive phase), September (refractory phase), and December (sensitive phase) of 2018. Immediately after procurement, birds were brought to the laboratory. Bodyweight, bill color, molt in body feathers, and testes size were recorded. The next day, all the birds were sacrificed in the middle of the day. Blood was collected and serum was used for ELISA of corticosterone, triiodothyronine (T3), and thyroxine (T4). mRNA levels of thyroid-stimulating hormone-β (Tshβ), type 2 deiodinase (Dio2), type 3 deiodinase (Dio3), gonadotropin-releasing hormone (GnRh), and gonadotropin inhibitory hormone (GnIh) were measured in hypothalamic tissue. Urban birds showed higher levels of corticosterone during the stimulatory phase. There was a delay in the initiation of testicular growth in urban birds and it was supported by reduced levels of T3 in blood plasma and relatively lower transcription of Dio2 and GnRH mRNA in urban birds. Our findings suggest that the urban environment delays the timing of reproduction in birds and could be the consequence of local environmental conditions.
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Affiliation(s)
| | | | - Amit Kumar Trivedi
- Department of Zoology, Mizoram University, Aizawl, Mizoram, 976004, India.
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Renthlei Z, Hmar L, Kumar Trivedi A. High temperature attenuates testicular responses in tree sparrow (Passer montanus). Gen Comp Endocrinol 2021; 301:113654. [PMID: 33129830 DOI: 10.1016/j.ygcen.2020.113654] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 10/23/2020] [Accepted: 10/25/2020] [Indexed: 10/23/2022]
Abstract
The majority of birds use environmental cues to time their reproduction. Photoperiod is the most dominant cue, but other environmental factors may play a critical role in successful reproduction. Some previous studies show the effect of temperature on the timing of nest building and reproduction. Here we tested if the temperature can modulate the reproductive responses of tree sparrows. Three experiments were performed on adult male birds. In experiment 1, birds (n = 5/group) were exposed to either high (30 ± 2 °C) or low temperature (20 ± 2 °C). Change in body mass, bill color, and testes volume was recorded every 30 days. In experiment 2, a similar temperature protocol was followed, but birds were euthanized after 30 days. In experiment 3, birds were first exposed to SD (8L:16D) for 30 days but either with high (30 ± 2 °C) or low temperature (20 ± 2 °C). After 30 days, birds were exposed to LD (14L:10D), but half of the high-temperature birds were moved to low temperature, and half of the low-temperature birds were moved to high temperature. After 30 days, all birds were euthanized. In experiment 2 and 3 immediately after euthanization birds, blood samples were collected, serum was used for hormone assay. mRNA levels of thyroid-stimulating hormone-β (Tshβ), type 2 deiodinase (Dio2), type 3 deiodinase (Dio3), gonadotropin-releasing hormone (GnRH) and gonadotropin inhibitory hormone (GnIH) were measured in hypothalamic tissue. Results from experiment 1 show that high temperature attenuates the testicular responses and accelerates the timing of regression. Experiment 2 shows that on day 30, testicular responses are similar, but reproductive genes express differentially in two groups. Experiment 3 shows that exposure to high temperatures during the photosensitive stage affects the testicular response at the poststimulatory state. Together, these findings suggest that high temperature modulates reproductive responses of tree sparrow.
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Affiliation(s)
| | - Lalruatthara Hmar
- Department of Zoology, Mizoram University, Aizawl, Mizoram, 976004, India
| | - Amit Kumar Trivedi
- Department of Zoology, Mizoram University, Aizawl, Mizoram, 976004, India.
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Dixit AS, Byrsat S, Singh NS. Circadian rhythm in photoperiodic expressions of GnRH-I and GnIH regulating seasonal reproduction in the Eurasian tree sparrow, Passer montanus. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2020; 211:111993. [PMID: 32818912 DOI: 10.1016/j.jphotobiol.2020.111993] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 05/03/2020] [Accepted: 08/09/2020] [Indexed: 10/23/2022]
Abstract
The present study investigates the involvement of circadian rhythm in photoperiodic expressions of GnRH-I and GnIH in the hypothalamus controlling seasonal reproduction in the Eurasian tree sparrow (Passer montanus). Groups of photosensitive birds were exposed for four weeks to resonance light dark cycles comprising of a light phase of 6 h (L) combined with dark phase of different durations (D) such that the period of LD cycles varied by 12 h increments viz. 12- (6 L/6D), 24- (6 L/18D), 36- (6 L/30D), 48- (6 L/42D), 60- (6 L/54D) and 72- (6 L/66D)h. In addition, a control group (C) was maintained under long day length (14 L/10D). Observations, recorded at the beginning and end of experiment, revealed significant testicular growth with corresponding increase in the hypothalamic expression of GnRH-I peptide but low levels of GnIH mRNA and peptide in the birds exposed to resonance cycles of 12, 36 and 60 h which were read as long days. On the other hand, birds experiencing resonance cycles of 24, 48 and 72 h read them as short days wherein they maintained their quiescent gonads and low levels of GnRH-I peptide but exhibited significant increase in GnIH mRNA and peptide expressions. Thus, sparrows responded to resonance light dark cycles differently despite the fact that each of them contained only 6 h of light. These findings suggest that an endogenous circadian rhythm is involved in photoperiodic expressions of above molecules and indicate a shift in their expressions depending upon whether the light falls in the photoinducible or non-photoinducible phase of an endogenous circadian rhythm.
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Affiliation(s)
- Anand S Dixit
- Department of Zoology, North Eastern Hill University, Shillong-22, Meghalaya, India.
| | - Sanborlang Byrsat
- Department of Zoology, North Eastern Hill University, Shillong-22, Meghalaya, India
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Dixit AS, Singh NS. Circadian versus circannual rhythm in the photoperiodic programming of seasonal responses in Eurasian tree sparrow (Passer montanus). Photochem Photobiol Sci 2020; 19:371-381. [DOI: 10.1039/c9pp00404a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Experiments were done on the subtropical tree sparrow to examine whether day length, as a proximate factor, involves circadian rhythm in timing seasonal responses or these events are programmed by the mediation of endogenous circannual rhythm.
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Affiliation(s)
- Anand S. Dixit
- Department of Zoology
- North-Eastern Hill University
- Shillong-793022
- India
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Temperature modulates photoperiodic seasonal responses in the subtropical tree sparrow, Passer montanus. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2018; 204:721-735. [DOI: 10.1007/s00359-018-1272-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 06/11/2018] [Accepted: 06/11/2018] [Indexed: 01/29/2023]
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Dixit AS, Singh NS, Byrsat S. Role of GnIH in photoperiodic regulation of seasonal reproduction in the Eurasian tree sparrow. J Exp Biol 2017; 220:3742-3750. [DOI: 10.1242/jeb.164541] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 08/10/2017] [Indexed: 12/15/2022]
Abstract
Seasonal reproductive cycles of most birds are regulated by photoperiod via neuroendocrine control. GnIH in hypothalamus has been reported to act as neuroendocrine integrator of photoperiodic cues. In this study, both captive and field investigations were carried out to understand the effects of photoperiod and seasonality on GnIH expression in subtropical tree sparrows. Monthly observations on GnIH mRNA and peptide expressions in wild birds over a year revealed significant increase in GnIH mRNA level and number of GnIH-ir neurons during the nonbreeding season when compared to their expressions in the breeding season. GnIH-ir neurons were found primarily in paraventricular nucleus (PVN) with their fibers projecting into median eminence and some other areas of brain. In an eight month long experiment, birds exposed to short days had higher GnIH expression compared to birds on long days regardless of sampling month. Long day birds with regressed testes had similar GnIH levels compared to short day birds. Though the number of GnIH peptide expressing neurons ran almost parallel to the levels of GnIH mRNA, they were found inversely related to gonadal size in both sexes under natural and artificial photoperiodic conditions. These results clearly indicate inhibitory role of GnIH in photoperiodic regulation of seasonal reproduction in the tree sparrow.
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Affiliation(s)
- Anand S. Dixit
- Department of Zoology, North-Eastern Hill University, Shillong-22, India
| | - Namram S. Singh
- Department of Zoology, Cotton University, Guwahati-01, India
| | - Sanborlang Byrsat
- Department of Zoology, North-Eastern Hill University, Shillong-22, India
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