Hemidactylus Flaviviridis Research Articles

Cellular mechanism of estrogen‐induced thymic involution in wall lizard: caspase‐dependent action

The present study, for the first time in an ectothermic vertebrate, demonstrates the cellular mechanism of estrogen-induced thymic involution. Ovariectomy in lizards during the preparatory phase of the reproductive cycle resulted in distinct differentiation of cortico-medullary regions and increase in cellularity, especially in the cortical region. The ovariectomy-induced changes were reversed following administration of 17-estradiol (E2), suggesting a primary role of E2 in causing thymic atrophy. To understand the cellular mechanism of E2-induced thymic atrophy, in vitro effect of E2 was investigated on thymocyte proliferation and apoptosis. E2 decreased the uptake of tritiated thymidine (3H-TdR) by thymocytes in a dose-dependent manner, suggesting that estrogen directly inhibits the thymocyte proliferation. Unlike proliferation, E2 did not have any direct effect on thymocyte apoptosis, as evident by DNA gel electrophoretic, flow cytometric or fluorescence microscopic studies. However, in the presence of thymic epithelial cell-rich stromal components (TEC), E2 treatment at low or high concentrations resulted in depolarization of plasma membrane, DNA fragmentation and decrease in DNA content. This suggests that E2 indirectly, through TEC-secreted factors, controls thymocyte apoptosis. Similar result was observed following fluorescence microscopy. The indirect effect of E2 was further ascertained with the findings that E2-pretreated TEC-conditioned medium accelerated the thymocyte apoptosis. Nevertheless, exposure of thymocytes to E2 was seen to be inevitable for the apoptotic action of TEC-secreted paracrine factors. In the presence of TEC, a positive reaction for caspase-3, -7 and -9 and enzyme substrate, poly(ADP-ribose) polymerase (PARP) in response to E2 suggests the caspase-dependent thymocyte apoptosis in the wall lizard Hemidactylus flaviviridis. Further, E2 was shown to act through genomic pathway, since the receptor antagonist tamoxifen and transcription/translation inhibitors blocked its apoptotic action. Interestingly, the apoptotic effect of E2 was effectively decreased by progesterone.

Mechanism of androgen-induced thymic atrophy in the wall lizard, Hemidactylus flaviviridis: An in vitro study

The present in vitro study demonstrates the effect of androgen on thymocyte apoptosis leading to thymic atrophy in the wall lizard, Hemidactylus flaviviridis. Thymocytes collected from castrated lizards were incubated with varying concentrations of dihydrotestosterone (DHT) to observe its effect on proliferation and apoptosis. DHT treatment reduced the tritiated thymidine incorporation in thymocytes, suggesting that androgen directly inhibits thymocyte proliferation. It also caused apoptosis of thymocytes effectively at 10 −7 M. However, the increased apoptotic action of DHT was indirectly mediated through thymic epithelial cell-rich stromal cell components (TEC). This observation was reaffirmed by in vitro incubation of thymocytes with DHT-pretreated TEC-conditioned medium. However, the DHT-induced TEC-secreted apoptotic factors could induce thymocyte DNA fragmentation only when DHT was added to the conditioned medium. It implies that DHT priming of thymocytes is required for the apoptotic effect of DHT-induced TEC-secreted factor. DHT-induced thymocyte apoptosis was found to be caspase-dependent since it activated the initiator (caspase-9) and effector caspases (caspases-3 and -7) as well as cleaved the enzyme substrate poly(ADP-ribose) polymerase (PARP). Further, the apoptotic effect of DHT was routed through its classical receptors, as non-steroidal antiandrogen flutamide blocked the DHT-induced thymocyte apoptosis. The inhibition of apoptosis by transcription/translation inhibitors further substantiates the genomic pathway of DHT action. It can be concluded that DHT, in addition to inhibiting thymocyte proliferation directly, accelerates caspase-dependent apoptotic process in thymocytes indirectly through TEC via a genomic pathway. Nevertheless, the priming of thymocytes with DHT is required for the apoptotic effect of TEC-secreted factor.

Endocrine and paracrine control of Leydig cell steroidogenesis and proliferation in the wall lizard: an in vitro study

The present in vitro study, for the first time, demonstrates the endocrine as well as paracrine control of Leydig cell steroidogenesis and proliferation in the wall lizard Hemidactylus flaviviridis. Unlike mammals, Leydig cell activity in the wall lizard seems to be directly controlled by ovine follicle-stimulating hormone (FSH)-like molecule, since FSH increased the testosterone production and tritiated thymidine ([ 3H]TdR) incorporation by Leydig cells. In addition, Sertoli cell paracrine factor or factors play important roles in controlling Leydig cell activities as non-activated Sertoli cell-conditioned medium (SCCM) alone stimulated testosterone production by both non-activated and FSH-preactivated Leydig cells. As far as the proliferation was concerned, non-activated SCCM did not influence [ 3H]TdR uptake by non-activated or FSH-preactivated Leydig cells, while FSH-preactivated SCCM was able to stimulate proliferation of activated Leydig cells. It may be concluded that FSH, besides directly controlling, also regulates Leydig cell activities indirectly through stimulating the secretion of Sertoli cell paracrine factors. Moreover, steroidogenic factor is different from mitogenic factor because non-activated Leydig cells were responsive to steroidogenic factor but nonresponsive to mitogenic factor.

Dual mode of catecholamine action on splenic macrophage phagocytosis in wall lizard, Hemidactylus flaviviridis

In the present study, in vitro concentration-related effect of catecholamines, dopamine (DA), norepinephrine (NE), and epinephrine (E) was observed on phagocytic activity of splenic macrophages to understand the impact of sympatho–adrenal–medullary (SAM) activation on innate immunity in wall lizard Hemidactylus flaviviridis under stress condition. Restraint stress for 1 h resulted in marked suppression of macrophage phagocytosis, suggesting that supra-physiological level of catecholamines in response to SAM activation under stress suppressed phagocytosis. This interpretation was reinforced since all the catecholamines considerably reduced phagocytosis at high concentrations ranging from 10 −7 to 10 −5 M. On the contrary, DA, NE, and E at low concentrations considerably stimulated phagocytosis, which increased with the decrease of concentrations ranging from 10 −11 to 10 −15 M. Further, effect of NE and E was blocked by β-adrenergic blocker suggesting the β-adrenoceptor-dependent regulating mechanism of NE and E. DA acts through both β-adrenoceptor-dependent and D1/D2 class receptor-dependent mechanism, since β-adrenergic blocker could partially block the DA effect. β-Adrenoceptor-linked adenylate cyclase-mediated cAMP action in modulation of phagocytic activity was evident as 3-isobutyl-1-methyl-xanthine suppressed phagocytosis. Further, to delineate the mode of dual effect of catecholamines through β-adrenergic receptors, in vitro concentration-related effect of cAMP was investigated on macrophage phagocytosis. cAMP depending on concentration had opposite effect on phagocytosis, and its stimulatory effect at low concentrations was reversed by actinomycin D and cycloheximide, whereas these transcription and translation inhibitors, respectively, failed to alter the inhibitory effect of cAMP at high concentrations. This suggests the concentration-related two different pathways of catecholamine action, classical non-genomic at high concentration while genomic pathway at low concentration.

Glucocorticoid-induced thymocyte apoptosis in wall lizard Hemidactylus flaviviridis

The aim of the present study is to demonstrate the phenomenon and mechanism of GC-induced cell death of thymocytes in wall lizard Hemidactylus flaviviridis. Lizard thymocytes were treated in vitro with different concentration of corticosterone (CS) for varying durations and the genomic DNA was analyzed both by agarose gel electrophoresis and flow cytometry. Corticosterone induced DNA fragmentation in a dose-dependent manner, as the DNA laddering was more prominent at 10 −14 M than at lower concentrations. However, CS could activate the programmed cell death of thymocytes only when incubated for 48 h and not at 3, 6, 12, or 24 h. Similar results were obtained following the flow cytometric analysis. The highest apoptotic cell death was noted at 10 −14 M concentration. CS-induced programmed cell death was decreased dramatically when the thymocytes were preincubated with RU 486 (10 −9 ng /ml) for 24 h, suggesting the classical receptor-mediated genomic pathway of glucocorticoid action in inducing apoptosis of thymocytes in wall lizard H. flaviviridis.

Dose and time-related in vitro effects of glucocorticoid on phagocytosis and nitrite release by splenic macrophages of wall lizard Hemidactylus flaviviridis

Glucocorticoids (GC) are usually considered to be immunosuppressive and anti-inflammatory. However, recent studies in mammals have demonstrated the diverse effects of GC on non-specific host-defense mechanism, depending on dose or duration of treatment. Hence, in the present study in vitro dose and time-related effects of glucocorticoid, i.e. hydrocortisone (HC) on phagocytosis and nitrite production by LPS-induced splenic macrophages in wall lizard Hemidactylus flaviviridis has been investigated. Hydrocortisone suppressed percentage phagocytosis, phagocytic index and nitrite production by splenic macrophages even at the lowest concentration (10 −13 M) for a short-term exposure (4 h). Hydrocortisone-induced suppression enhanced with the increase of concentration or duration of exposure time. The suppressive effect of hydrocortisone on phagocytic and cytotoxic activities of splenic macrophages was further corroborated since the pre-exposure of macrophages to glucocorticoid-receptor blocker (RU 486) considerably reduced the hydrocortisone-induced suppression of phagocytosis and nitrite production. The present study suggests that GC instead of diverse effects, has dose- and time-dependent immunosuppressive effect on non-specific host-defense immune responses in wall lizard H. flaviviridis.

In Vitro Effect of Sex Steroids on Cytotoxic Activity of Splenic Macrophages in Wall Lizard (Hemidactylus flaviviridis)

Sexual dimorphism was observed in nitrite release and IL-1-like molecule production by splenic macrophages of the wall lizard (Hemidactylus flaviviridis), with a higher level in females than in males. Gonadectomy in both males and females resulted in a considerable increase of nitrite and IL-1-like molecule secretion, suggesting that the sex hormones inhibit cytotoxic activity of macrophages. To verify this assumption, dose- and time-related in vitro experiments with male and female sex steroids, dihydrotestosterone (DHT) and 17β-estradiol (E2), respectively, were carried out. E2 and DHT both significantly reduced the nitrite release and IL-1-like molecule production with an increase of dose or duration of treatment.

In vitro effect of temperature on phagocytic and cytotoxic activities of splenic phagocytes of the wall lizard, Hemidactylus flaviviridis

The in vitro effect of temperature on phagocytosis, nitric oxide production and interleukin-1 (IL-1) secretion by splenic phagocytes isolated from the wall lizard ( Hemidactylus flaviviridis) demonstrated that changes in temperature altered non-specific defenses. The LPS-induced percentage phagocytosis and phagocytic index were recorded maximum at 25°C. The phagocytic activity declined considerably when the phagocytes were incubated at low (7 and 15°C) or high (37°C) temperatures. The presence of bacterial lipopolysaccharide (LPS) in the incubation medium could considerably enhance the phagocytic activity of splenic phagocytes. A similar temperature-related effect was also observed on LPS-induced cytotoxic activity of phagocytes. LPS could stimulate the nitrite release indicating nitric oxide production only at 25°C. Likewise, the proliferative responses of immature rat's thymocytes to LPS-induced phagocyte-conditioned medium suggest that IL-1 secretion was enhanced when phagocytes were cultured at 25°C. This suggests that 25°C is the optimal temperature for phagocyte functions in H. flaviviridis. The decrease or increase in temperature other than at 25°C dramatically suppressed the phagocyte activities.

Pattern of Recruitment, Growth of Developing Follicles, and Germinal Bed Activity in the Tropical Gecko, Hemidactylus brooki

Reproductive cycles have been studied in many species of lizards from both tropical and temperate regions (Fox, 1977; Duvall et al., 1982; Fitch, 1982; Vitt, 1982, 1986, 1992; Vitt and Goldberg, 1983; Licht, 1984; James and Shine, 1985; Whittier and Crews, 1987; Sarkar and Shivanandappa, 1989; Clerke and Alford, 1993; Shanbhag and Prasad, 1993; Flemming, 1994; Ramirez Pinilla, 1995; Huang, 1996). Lizards inhabiting temperate regions typically breed seasonally. Their gonadal development is essentially synchronous within a population, resulting in a short, well defined breeding season (Licht, 1984). Some species of lizards inhabiting the sub-tropics and tropics also breed seasonally (Licht, 1984; Vitt and Blackburn, 1991; Shanbhag and Prasad, 1993; Huang, 1996) but exhibit a longer breeding season. Though species living in the humid tropics are known to breed year round (see Licht, 1984), a few of them are seasonal breeders (Vitt and Blackburn, 1991). Among geckonids, the Javanese geckos, Cosymbotus platyrus, Hemidactylus frenatus, Peropus mutilatus, and the Australian lizard, Leiolepisma rhomboidalis are continuous breeders (Church, 1962; Wilhoft, 1963). On the other hand, H. frenatus breeds seasonally on Islands of Ryukyu Archipelago and in Taiwan (Lin and cheng, 1984; Ota, 1994). The house gecko Hemidactylus flaviviridis, is known to breed between mid-March and mid-May in northwestern India (Verma and Guraya, 1975). In south India Hemidactylus brooki is a very common household gecko, and is also encountered in Sri Lanka, Burma, Western Malaysia, and various islands in Indonesia and Philippines (Welch et al., 1990). Little is known about the reproductive biology of this lizard. Furthermore, studies on the ovarian follicular dynamics are limited to two species of geckos, Lepidodactylus lugubris and H. frenatus (Jones et al., 1978; Jones and Summers, 1984) and one species of polyautochornous (each ovary produces several eggs at a time) agamid lizard, Calotes versicolor (Shanbhag and Prasad, 1993). The present work was undertaken on H. brooki to study (1) the pattern of the female reproductive cycle, and (2) the follicular dynamics and germinal bed activity (production of oogonia and oocytes) during the ovarian cycle. Hemidactylus brooki (N = 229) were collected every fortnight from October 1992-September 1993 from households in Dharwad, Karnataka State, India (15?27'N, 75?01'E). Meteorological data were obtained from the local observatory at the University of Agricultural Sciences, Dharwad. At autopsy, snout vent length (SVL) and weights of the body, ovaries, oviducts, and liver of each lizard were recorded. In gravid lizards, the weight of oviduct along with eggs was recorded. The somatic weights were calculated by subtracting weights of the ovary and oviducts from body weights of individual lizards. The ovaries were fixed in Bouin's fluid, then dehydrated in graded series of alcohol, cleared in benzene, and embedded in paraffin. Transverse serial sections, 6p-m thick, of the right ovary, were stained with Hematoxylin-eosin. The sections were examined under 40x magnification to scan for previtellogenic, vitellogenic, and atretic (AF) follicles, and corpora lutea (CL). The diameter of the largest follicle in each ovary was measured using an ocular grid under 8x magnification. ANCOVA was performed on log transformed data of ovary, oviduct, and liver weights, with body mass as covariate and month as the class interval to exam-

Effects of body mass, temperature, and season on resting metabolism of the nocturnal gecko Hemidactylus flaviviridis

The resting metabolic rate (RMR) of Hemidactylus flaviviridis was measured at different temperatures from 20 to 35°C during winter and summer acclimatization. The mass exponent b values ranged between 0.67 and 0.72. Winter-acclimatized geckos of various body masses had significantly lower RMRs than summer-acclimatized geckos only at 20°C. It seems that low thermal sensitivity for summer–acclimatized group may facilitate activity during its active seasons, and high thermal sensitivity between 20 and 25°C for winter–acclimatized group may conserve energy during inactivity in winter.

Epididymal influence on acquisition of sperm motility in the gekkonid lizard Hemidactylus flaviviridis.

Total sperm count and percent sperm motility were noted in different parts of the epididymis, and the effect of anterior, middle, and posterior epididymal fluid on the induction of motility of nonmotile testicular spermatozoa was observed. The results were used to compare the influence of different parts of epididymis of Hemidactylus flaviviridis on the acquisition of sperm motility, which is a sign of sperm maturation. Spermatozoa collected from different regions of the ductus epididymidis showed considerable difference in their motility as well as total count with an increase from anterior to posterior region. The epididymal fluids from different regions induced the motility of testicular spermatozoa and the induction accelerated with increasing fluid volume and incubation period. Epididymal fluid at higher volumes induced the motility of nonmotile testicular spermatozoa significantly even at short-term incubation. Among different epididymal regions, fluid from posterior was more potent in influencing the motility than the fluids of middle and anterior. Motility pattern of spermatozoa varied from zig-zag, circular, and erratic in anterior to wavy in posterior region of epididymis. However, the mean sperm velocity did not show any regional variation.

Tail Regeneration in Normal, Blinded and Pinealectomized Gekkonid Lizards, Hemidactylus flaviviridis, Exposed to Four Different Light Conditions During Three Seasons (Temperatures)

AbstractTail regeneration was followed for 60 days in 1470 normal (NL), blinded (BL) and pinealectomized (PX) gekkonid lizards, Hemidactylus flaviviridis, fed on cockroaches ad libitum and exposed to continuous light of high intensity (2500 lux), continuous light of low intensity (638 lux), 12 h of light (high intensity) and 12 h of darkness and continuous darkness in summer (March – May; cage temperature 30°C) monsoon (August – October; cage temperature 26°C) and winter (November – January; cage temperature 17°C) seasons. A comparative assessment of the new growth (regenerate) showed that the initiation of regeneration, the daily growth, the total length of tail replaced at the end of regeneration and the total percentage replacement of the lost (autotomized) tails were all enhanced by continuous light and depressed by continuous darkness. Furthermore, there was no significant difference between any of the parameters in NL and BL Hemidactylus; however, PX lizards generally showed retardation in the regeneration process. Seasonal differences in tail regeneration were noted—the best regenerative performance was obtained during the summer months and the worst during the winter months, with the regenerative performance during the monsoon season in between. Thermal and photoperiodic influences on tail regeneration in lizards are discussed.

Is the pineal involved in the stimulatory influence of prolactin on tail regeneration in lizards? Studies with exogenous prolactin in lizards exposed to continuous darkness

We have recently demonstrated that continuous light stimulates tail regeneration in the gekkonid lizard, Hemidactylus flaviviridis, whereas continuous darkness and pinealectomy depress regeneration. As a sequel to this observation, the effect of exogenous ovine prolactin (oPRL) on tail regeneration in normal (NL) and pinealectomized (PX) Hemidactylus exposed to continuous darkness (L:D 0:24) during the monsoon season was investigated. Once-daily intraperitoneal (ip) injections of 500 μg/kg oPRL were administered to a group of NL lizards, a group of PX lizards, and a group of sham-PX (sPX) lizards, 5 days prior to tail autotomy and 50 days afterward. Three groups—PX, sPX, and NL animals—served as the controls and received once-daily ip injections of 0.6% saline. Our observations show that initiation of regeneration, daily growth rate, total length of new growth (regenerate) at the end of regeneration, and total percentage replacement of lost (autotomized) tail were all significantly enhanced in oPRL-treated NL lizards as compared with their saline-treated (NL, PX, and sPX) and oPRL-treated (PX and sPX) counterparts. It is suggested that PRL may be the active factor that speeds up the rate of tail regeneration in lacertilians. The role of the pineal organ in vertebrate photoreception and the possibility that in Hemidactylus the presence of an intact pineal is somehow linked with the favorable influence of PRL on tail regeneration are discussed.

Dopamine antagonist speeds up tail regeneration in lizards exposed to continuous darkness: evidence for prolactin involvement.

In earlier studies, we demonstrated that continuous light (LL:LD, 24:0) stimulated tail regeneration whereas continuous darkness (DD:LD, 0:24) and pinealectomy depressed the same in the Gekkonid lizard, Hemidactylus flaviviridis, and, furthermore, exogenous prolactin significantly enhanced the regeneration process in lizards kept in 0:24 LD. However, the regeneration process in animals exposed to 24:0 LD was unaffected by the dopamine agonist, bromocriptine. This study with pimozide, an antipsychotic drug, and a potent dopamine receptor antagonist was conducted to ascertain whether the dopaminergic regulation of prolactin release is operative in lizards, as in mammals, and to provide further evidence for prolactin involvement in regenerative growth. Once daily intraperitoneal injection of 50 micrograms/kg pimozide to H. flaviviridis, 5 days prior to tail autotomy and 50 days thereafter, stimulated the regeneration process in lizards exposed to 0:24 LD. The initiation of regeneration, the total length of new growth (regenerate) produced by Day 50, and the total percentage replacement of the lost (autotomized) tails at the end of 50 days of experimentation were all significantly enhanced in pimozide-treated animals as compared with their counterparts injected with 0.6% sterile saline; in fact, better than saline-injected controls exposed to 24:0 LD of 638 lux intensity. The daily growth rate was also enhanced in pimozide-treated lizards. Interestingly, the pattern of regeneration as well as the final regenerate of pimozide-treated lizards were similar to those observed earlier in ovine prolactin-treated animals exposed to similar experimental photoperiodic schedules.(ABSTRACT TRUNCATED AT 250 WORDS)

Parachlorophenylalanine Retards Tail Regeneration in the Gekkonid Lizard Hemidactylus Flaviviridis Exposed to Continuous Light

Parachlorophenylalanine (p-CPA) was used for chemical pinealectomy in a study of tail regeneration in the gekkonid lizard, Hemidactylus flaviviridis. Two doses of p-CPA (200 or 400 micrograms kg-1 body mass) were injected into two groups of lizards (5 days prior to and 30 days after caudal autotomy) exposed to continuous light of 2500 lx intensity during the summer season (March-May). Our observations show that the initiation of regeneration, the daily growth rate, the total length of new growth (regenerate) produced, and the total percentage replacement of the lost (autotomized) tails 30 days after autotomy were all significantly less with 400 micrograms kg-1 and insignificantly less with 200 micrograms kg-1 of p-CPA than in the control group of animals. The results may indicate that the effect of the drug p-CPA, an agent employed for chemical pinealectomy, on tail regeneration in H. flaviviridis is dose-dependent and that p-CPA at the high dose of 400 micrograms kg-1 has a similar retardation effect to that of complete pineal ablation. The role of the pineal in photoperiodic photoreception, and the effect of p-CPA on serotonin-melatonin biosynthesis and the consequent effects on tail regeneration, are discussed.

Preliminary evidence for pineal-mediated extraretinal photoreception in relation to tail regeneration in the Gekkonid lizard, Hemidactylus flaviviridis.

The tail of the Gekkonid lizard Hemidactylus flaviviridis was autotomized and the animals were subjected to eight different photoperiodic schedules during the process of tail regeneration. Our previous observation had shown that long-day photoperiods stimulate the regeneration process, whereas short-day photoperiods depress it. Furthermore, it has also been demonstrated that the lateral eyes, or retinae, do not participate in photoperiodically significant photoreception in H. flaviviridis, as blinded Hemidactylus regenerated their autotomized tails like their sighted counterparts exposed to similar experimental photoregimes. In a further attempt to localize the site(s) of photoreception in these animals, one group of lizards had their heads painted with a mixture of Indian ink and Nile blue sulphate (II-NBS) [NL (HP)] in order to prevent light from penetrating to the pineal gland, and another group had their pineal glands surgically removed (pinealectomy, Px); the regenerative potentials were compared with their normal (NL) counterparts. Our results showed that the initiation and onset of regeneration, the daily growth rate, the total new growth (regenerate) produced at the end of regeneration and the total percentage replacement of the lost (autotomized) tails were significantly retarded in Px and NL (HP) animals, compared with the NL (unoperated and nonpainted) ones. Since pinealectomy as well as light deprivation to the pineal abolished the stimulatory influence of long-length photoperiods, the pineal gland is discussed here as a major transmitter of photic stimulus in lacertilian tail regeneration. It is presumed that in the lizard, as in mammals and some birds, the pineal gland acts by way of the neuroendocrine complex and/or the hypothalamohypophyseal axis.

Effects of mammalian pituitary gonadotropins on the seasonally quiescent ovary of the Indian wall lizard, Hemidactylus flaviviridis

Adult Indian wall lizards, Hemidactylus flaviviridis (Rüppell) with seasonally quiescent ovaries were treated either with ovine FSH or LH. Quantitative as well as histochemical observations revealed that only FSH could stimulate the ovarian growth and steroidogenesis whereas LH had no effect either on ovarian growth or on ovarian steroidogenesis.

Epididymis of the Indian wall lizard (Hemidactylus flaviviridis) during the sexual cycle and in response to mammalian pituitary gonadotropins and testosterone.

AbstractThe histology and histochemistry of the epididymis of the Indian wall lizard Hemidactylus flaviviridis (Rüppell) was studied in normal and hormone‐treated males. The ductus epididymidis showed a considerable variation in epithelial cell height and lumenal diameter along its length. It can be divided approximately into anterior, middle, and posterior regions. Epithelial cell height was maximal in the middle region and minimal in the posterior region. The lumen of the ductus epididymidis increased markedly in diameter from anterior to posterior ends with a concomitant increase in the sperm density. During the breeding phase, epithelial cell height and lumenal diameter of both ductuli and ductus epididymidis become markedly enlarged. The epithelium of reproductively active ducts was filled with secretory granules. Both the secretory granules of the epithelium and the secretory material mixed with sperm in the lumen showed a positive reaction to Sudan Black‐B, indicating the presence of lipid. The relative effects of mammalian FSH and LH on the regressed epididymis revealed that only FSH was capable of stimulating the growth and secretory activity of the epididymis.

Effects of mammalian pituitary gonadotropins and testosterone on the testes of sexually quiescent Indian wall lizard, Hemidactylus flaviviridis (Rüppell)

Effects of mammalian FSH, LH and testosterone on sexually regressed testes of Hemidactylus flaviviridis were investigated. Quantitative as well as histochemical studies revealed that only FSH could stimulate spermatogenesis and steroidogenesis. LH showed no effect either on the spermatogenesis or on steroidogenesis. Although testosterone did not induce any change at the initial stage, when given for a longer period the division of spermatogonia was completely checked.

The Genera Barrouxia, Defretinella, and Goussia of the Coccidian Family Barrouxiidae (Protozoa, Apicomplexa)1

ABSTRACTThe apicomplexan family Barrouxiidae Léger, 1911 is reviewed and revised on the basis of present information. It includes the genera Barrouxia Schneider, 1885 with ten named species, Defretinella Henneré, 1966 with one named species, and Goussia Labbé, 1896 with 25 named species. The family is characterized by having bivalved sporocysts with a longitudinal suture line. Available information, admittedly spotty, is given for each species on oocyst, sporocyst and sporozoite structure, and on locus of sporulation. The following seven new combinations are made: Goussia flaviviridis (Setna & Bana, 1935) n. comb. in the gecko Hemidactylus flaviviridis; G. hyalina (Léger, 1898) n. comb. in an unidentified aquatic beetle; G. lacazei (Labbé, 1895) n. comb. in the centipedes Lithobius forficatus and L. martini; G. metchnikovi (Laveran, 1897) n. comb. in the gobies Gobio gobio and G. albipinnatus; G. schaudinniana (Pinto, 1928) n. comb. in the centipede Lithobius forficatus; G. stankovitchi (Pinto, 1928) n. comb. in the small bleak Alburnus alburnus, the bream Abramis brama, and the red roach Scardinius erythrophthalmus; Goussia sp. (Dogel' Akhmerov, 1959) nov. comb. in the freshwater fish Gnathopogon chankaensis.