Physiology.pmd

Tariq Mahmood, M. Maqbool Ahmed, Muhammad Sajid Nadeem Abstract. The present study was undertaken to estimate the levels of reproductive hormones i. e: testosterone, estradiol and progesterone, to investigate the breeding biology of Houbara Bustard. The male and female birds were used from Houbara Research and Rehabilitation Center (HRRC) Rahim Yar Khan. The plasma blood samples of 5 male and 5 female birds were collected during non-breeding and breeding seasons. Then testosterone, estradiol and progesterone were measured by RIA (Radioimmunoassay). The results showed that there was no significant difference in the levels of testosterone during non-breeding and breeding seasons. The level of estradiol was lower during non-breeding season (9.70 ± 0.72 pg/ml) and higher during breeding season (14.35 ± 0.77 pg/ ml) and there was a significant difference in the levels during non-breeding and breeding seasons (p < 0.01).
There level of progesterone was higher during non-breeding season (0.72 ± 0.10 ng/ml) while it was lower during the breeding season (0.55 ± 0.10 ng/ml). Thus there was a significant difference in the values of progesterone during non-breeding and breeding seasons (p < 0.001).
Keywords: Pakistan, Houbara Bustard, Chlamydotis undulata,physiology, reproductive hormones.
Address: T. Mahmood, Department of Biological Sciences, Quaid-i-Azam University Islamabad, Pakistan.
Ïðîôèëü ïîëîâûõ ãîðìîíîâ ó ñàìöîâ è ñàìîê äæåêà â òå÷åíèå ãîäà. - Ò. Ìàõìóä, Ì.Ì. Àõ- ìåä, Ì.Ñ. Íàäèì. - Áåðêóò. 13 (1). 2004. - Óðîâíè ïîëîâûõ ãîðìîíî⠖ òåñòîñòåðîíà, ýñòðàäèîëà è ïðîãåñòåðîíà – èçó÷àëèñü â Öåíòðå ïî èññëåäîâàíèþ è ðåàáèëèòàöèè äæåêà â Ðàõèì ßð Õàíå (Ïàêèñ- òàí). Ïëàçìà êðîâè 5 ñàìöîâ è 5 ñàìîê áðàëàñü âî âðåìÿ ãíåçäîâîãî è íåãíåçäîâîãî ïåðèîäîâ. Óðîâåíü ãîðìîíîâ èçìåðÿëñÿ ïðè ïîìîùè ðàäèîèììóííîãî àíàëèçà. Äîñòîâåðíûõ ðàçëè÷èé óðîâíÿ òåñòîñòåðî- íà â ãíåçäîâîé è âíåãíåçäîâîé ïåðèîäû íå îáíàðóæåíî. Óðîâåíü ýñòðàäèîëà áûë íèæå âî âíåãíåçäîâîé ïåðèîä (p < 0,01), à ïðîãåñòåðîíà – â ãíåçäîâîé (p < 0,001).
evated in spring (breeding season). Steimer et al. (1981) showed that estradiol 17-b formed Houbara bustard (Chlamydotis undulata) from testosterone in the brain is thought to be belongs to the bustard family Otididae. The involved in the hormonal control of male se- family is world wide in distribution, chiefly xual behaviour in some mammalian species.
inhabiting the open plains and semidesert re- Brenowitz et al. (1998) have shown that ex- gions. There are three sub-species of Houbara posing wild-caught White-crowned Sparrows bustard viz. Ch. u. macqueenii, Ch. u. undulata (Zonotrichia leucophrys) to long day photo- periods in the laboratory may not induce cir- Chlamydotis undulata macqueenii is culating concentrations of testosterone as high mainly winter visitor in Pakistan. Its breeding as those seen in the wild. Changes in circulat- season starts from February and continues till ing testosterone are primarily responsible for the end of June. Winter visitors from Central the seasonal morphological changes in the song Asia form the greater part of Pakistani Houbara nuclei. Testis size and circulating T concen- populations. Schwabl (1992) showed in mi- trations are greater in spring than in fall birds.
gratory European Robins (Erithacus rubecula) that the males defending winter territories ing biology Houbara, the present study was (non-breeding) had low while males defend- undertaken to estimate the levels of testoster- ing breeding territories had elevated levels of one, estradiol and progesterone during the non- LH and testosterone. Similarly in females, LH breeding and breeding seasons, to understand and estradiol levels were low in winter and el- the reproductive behaviour of this species.
T. Mahmood, M.M. Ahmed, M.S. Nadeem, 2004 Profile of gonadal hormones in Houbara Bustard sition. After 10 minutes the bound radioactiv- The present study was undertaken at HRRC counter. The results were analyzed by Student’s (Houbara Research and Rehabilitation Center) t-test.
Rahim Yar Khan, Pakistan, with the collabo- ration of Houbara Foundation International Rahim Yar Khan in the Cholistan desert lo- pipetted into the NSB (non-specific binding) cated 280 32 N and 700 55 E. The temperature and “A” tubes. Then 100 ml of each of the of the area was recorded from July 2001 to standards i.e., from “B” through “G” were pi- June 2002. The blood samples of 5 male and petted into the corresponding tubes. After that 5 female birds were collected regularly during 100 ml of each control and sample were pi- non-breeding (from September 2001 to Janu- petted into the corresponding tubes. Then 1 ary 2002) and breeding (from February 2002 ml of 125-I progesterone tracer was added to to June 2002) seasons. Each time 0.5 – 1.0 ml each of the tube. All the tubes were shaken on blood was obtained from the brachial vein of a vortex mixer and incubated for 3 hours at each bird. The blood was centrifuged at 3000 15–28°C. The free radioactive material was rpm for 10–15 minutes in the field laboratory decanted into a radioactive sink and the tubes of HRRC. In this way plasma was obtained, were placed in an inverted position for 10 min- sealed and stored in the freezer. Later on, the utes. The bound radioactivity was measured levels of testosterone, estrogen and progester- in a gamma counter and the results were ana- one were estimated using Radioimmunoassay lyzed by Student’s t-test.
allowed to thaw. 50 ml of standard, control and sample were successfully added to the rifles tubes. Then 500 ml of testosterone tracer was During the month of September, the plasma added to each of the tube. All the tubes were testosterone level was 0.23 ± 0.11 ng/ml, with shaken well and thoroughly mixed. The tubes a slight increase in December and January; and were incubated for 3 hours at 37°C in a water the values were 0.24 ± 0.14 ng/ml and 0.26 ± bath. Then all the free radioactive material was 0.14 ng/ml, respectively.
decanted in a radioactive sink. After 10 min- utes the bound radioactivity was measured in testosterone level was 0.30 ± 0.08 ng/ml. It slightly decreased during April. The values 100 ml of standard, control and sample were 0.33 ± 0.08 ng/ml and 0.30 ± 0.05 ng/ were successfully added to the antibody-coated ml, respectively. During the month of May tubes. Then 500 ml of tracer was added to each there was again a slight increase in the test- of the tube. The tubes were shaken for thor- osterone level and then slight decrease during ough mixing on a vortex mixer. Then the tubes June. The values were 0.32 ± 0.05 ng/ml and were incubated for 3 hours at 18–5°C with 0.31 ± 0.02 ng/ml, respectively (Table, Fig.
shaking (350 rpm). Then all the free radioac- 1). Thus there was no significant difference in tive material was decanted into a radioactive the levels of testosterone during non-breeding sink, the tubes were placed in an inverted po- and breeding seasons.
Average levels of Testosterone (ng/ml) in male, Estradiol (pg/ml) and Progesterone (ng/ml) during non-breeding (from September 2001 to January 2002) and breeding (from February to June 2002) seasons in female Houbara Bustard Ñðåäíèå óðîâíè òåñòîñòåðîíà (íã/ìë) ó ñàìöîâ, ýñòðàäèîëà (ïã/ìë) è ïðîãåñòåðîíà (íã/ ìë) âî âðåìÿ íåãíåçäîâîãî (ñåíòÿáðü 2001 ã. – ÿíâàðü 2002 ã.) è ãíåçäîâîãî (ôåâðàëü– èþíü 2002 ã.) ñåçîíîâ ó ñàìîê äæåêà Testosterone 0.23±0.11 0.24±0.14 0.26±0.14 0.30±0.08 0.33±0.08 0.30±0.05 0.32±0.05 0.31±0.02 8.50±0.98 9.70±1.00 10.80±0.86 9.50±0.92 10.20±0.93 14.20±0.60 15.60±0.75 21.99±2.40 Progesterone 1.62±0.08 2.80±0.22 0.74±0.16 0.39±0.04 0.41±0.04 0.61±0.04 0.76±0.05 0.60±0.04 month of June the estradiol level inclined to 21.99 ± 2.40 pg/ml (Table, Fig. 2). Thus dur- ing the non-breeding season the average es- During the month of September, the level tradiol level was comparatively low (9.70 ± of estradiol was 8.5 ± 0.98 pg/ml. It gradually 0.72 pg/ml) while during the breeding season increased during December and January and the plasma estradiol level was comparatively the values were 9.7 ± 1.00 pg/ml and 10.86 ± high (14.35 ± 0.77 pg/ml). Therefore, there was a significant difference in the values during non-breeding and breeding seasons (P < 0.01) During February the plasma estradiol level was 9.5 ± 0.92 pg/ml. It increased to 10.2 ± 0.93 pg/ml during March. Further gradual in- crease was observed during April and May , During the month of September, the plasma and the values were 14.2 ± 0.60 pg/ml and 15.6 progesterone level was 1.62 ± 0.08 ng/ml. It ± 0.75 pg/ml, respectively. Then during the increased during December up to 2.80 ± 0.22 Fig.1 . Levels of testosterone (ng/ml) during non-breeding and breeding seasons in male Houbara Ðèñ. 1. Óðîâíè òåñòîñòåðîíà (íã/ìë) âî âðåìÿ íåãíåçäîâîãî è ãíåçäîâîãî ïåðèîäîâ ó Profile of gonadal hormones in Houbara Bustard Fig. 2. Levels of estradiol (pg/ml) during non-breeding and breeding seasons.
Ðèñ. 2. Óðîâíè ýñòðàäèîëà (ïã/ìë) âî âðåìÿ ãíåçäîâîãî è íåãíåçäîâîãî ñåçîíîâ.
ng/ml. However, during January the progest- the level of progesterone was found to be high erone level decreased and its value was 0.74 ± (0.72 ± 0.10 ng/ml) when compared with that of breeding season (0.55 ± 0.03 ng/ml). Thus there was a significant difference in the values during non-breeding and breeding seasons.
was 0.39 ± 0.04 ng/ml. It gradually increased during March, April and May. The values were 0.41 ± 0.04 ng/ml, 0.61 ± 0.04 ng/ml and 0.76 The temperature of the area showed a great ± 0.05 ng/ml, respectively. However, during fluctuation. It was lowest in January 2002 while June it decreased to 0.60 ± 0.04 ng/ml (Table, maximum in June 2002 (Table 4). There was Fig. 3). Overall during non-breeding season no significant difference in the levels of test- Fig. 3. Levels of progesterone (ng/ml) during non-breeding and breeding seasons.
Ðèñ. 3. Óðîâíè ïðîãåñòåðîíà (íã/ìë) âî âðåìÿ ãíåçäîâîãî è íåãíåçäîâîãî ñåçîíîâ.
Aug.2001 Sep.2001 Oct.2002 Nov.2002 Dec.2001 Jan.2002 Feb.2002 Mar.2002 Apr.2002 May.2002 Jun.2002 Fig.4. Temperature record (mean minimum and maximum) at (non-breeding season) and HRRC, Rahim Yar Khan from July 2001 to June 2002.
Ðèñ. 4. Òåìïåðàòóðû (ñðåäíèé ìèíèìóì è ìàêñèìóì) â Öåí- ing).
òðå ïî èññëåäîâàíèþ è ðåàáèëèòàöèè äæåêà â Ðàõèì ßð Õàíå ñ èþëÿ 2001 ã. äî èþíÿ 2002 ã.
osterone during non-breeding and breeding during the breeding season. This is because seasons. This may be due to the fact that the during the breeding season the females were birds were in captive conditions rather than in fertile. Licht et al. (1982) showed that in the wild and so there was no expression of territo- Olive Ridley sea turtle (Lepidochelys olivacea) rial behavior, which is mostly noted in the other the levels of LH and progesterone increase birds. However, the male Houbara Bustard did more than an order of magnitude within a day display their plumage during the breeding sea- after oviposition.
son, which is the indicator of their sexual ma- Further research work is needed to under- turity. These results are in accordance with Bre- stand the complete breeding biology of Hou- nowitz et al. (1998) who showed that expos- bara Bustard, keeping in view some other pa- ing wild-caught white crowned sparrows to rameters like LH, FSH, and gonadal size etc.
long day photoperiods in the laboratory may in both wild and captive birds.
not induce circulating concentrations of test- osterone as high as those seen in the wild. Testis size and circulating concentrations of testoster- one are greater in spring than fall birds. Ac- Brenowitz E.A., Baptista L.F., Lent K., Wingfield J.C.
cording to Hunt et al. (1995) three passerines, (1998): Seasonal plasticity of the song control system in wild Nattal’s White-crowned Sparrows. - J. Neuro- Sparrow (Spizella arborea) and Savannah Hunt K., Wingfield J.C., Astheimer L.B., Buttemer W.A., Hahn T.P. (1995): Temporal patterns of territorial be- patterns of territorial aggression typical of spe- haviour and circulating testosterone in the Lapland cies. Well-defined territories are defended for Longspur and other arctic passerines. - Am. Zool.
several weeks, during which there is a prolon- Licht P., Owens D.W., Cliffton K., Penaflores C. (1982): ged peak in plasma concentrations of testoster- Changes in LH and progesterone associated with one. Similarly Schwabl (1992) showed that in nesting cycle and ovulation in the Olive Ridley sea migratory European Robins, the male defend- turtle, Lepidochelys olivacea. - Gen. Comp. Endo- ing winter territories (non-breeding) had low Schwabl H. (1992): Winter and breeding territorial be- while males defending breeding territories had haviour and levels of reproductive hormones of mi- elevated levels of LH and testosterone.
gratory European Robins. - Ornis. Scand. 23 (3): 271- There was a significant difference in the Steimer Th., Hutchison J.B. (1981): Androgen increase levels of estradiol during non-breeding and formation of behaviorally effective estrogen in Dove breeding seasons in female Houbara Bustard.
brain. - Nature. 292 (5821): 345-347.

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