Progesterone induction of pseudocopulatory behavior and stimulus-response complementarity in an all-female lizard species

Individuals of the all-female whiptail lizard species (Cnemidophorus) exhibit male-like and female-like pseudocopulatory behaviors that are correlated with stages of the ovarian cycle. Here we report on the hormonal bases of these behaviors. Parthenogenetic C. uniparens were ovariectomized and given Silastic implants containing either progesterone (P) or estradiol (E2); untreated controls received blank implants. Ten pairs of the following combinations were observed: P females paired with E2 females, P females paired with blank females, and E2 females paired with blank females. Each pair was observed at regular intervals 4 hr a day for 6 days. Pseudocopulations were observed between P and E2 animals; P animals consistently assumed the male-like role while E2 females assumed the female-like role. No pseudosexual behavior was observed between individuals of either P and blank or E2 and blank pairs. These data indicate that the postovulatory surge in P mediates male-like pseudosexual behaviors and the preovulatory surge in E2 mediates female-like pseudosexual behaviors in C. uniparens. Further, a complementarity in the behavior and physiology of both participants (male-typical mounting and female-typical receptivity) are important factors in pseudocopulatory behavior.     

Changes of AChE activity in ovarian nerves of pigs in different periods of the oestrous cycle: relationship to ovarian steroids

The morphological features of cholinergic nerves in the ovary, a determination of the level of acetylcholinesterase activity in different periods of the oestrous cycle and an attempt to determine if a relationship existe between AChE activity and the hormonal state of animal are described in this paper. Mature pigs were randomly assigned to 3 experimental groups and killed on 1st to 2nd d of oestrous cycle (group I; n = 6), on 13th to 14th d (group II; n = 7), and 16th to 18th d of the oestrous cycle (group III; n = 6). First signs of oestrus were designated the zeroth d. Histochemical evaluation of the most abundant cholinergic innervation was shown in ovaries of animals in group III, weaker cholinergic representation was found in animals of group I, and weakest in group II. Whereas the lowest activity of AChE determined by biochemical test was observed in the ovaries of group I, AChE activity in the ovaries on 13 to 14 and 16 to 18 d of oestrous cycle was 8- to 10-fold higher, respectively, in relation to the animals of group I. These results suggest that there exists a relationship between AChE activity in the ovary and ovarian steroid hormones and that this may be an important factor regulating the ovarian blood flow in the course of oestrous cycle in pigs.     

Fat body ovarian relationship in the garden lizard, Calotes versicolor (Daud.).

Abdominal fat body mass of Calotes versicolor showed annual changes that were universal related to the changes in ovarian somatic (GSI) and hepatosomatic (HSI) indices. Fat bodies were absent in late breeding phase (June-August). Thirty day fatectomy (FBX) during prebreeding phase significantly reduced GSI, HSI, and total number of extrastromal follicles; also, recruitment of vitellogenic follicles was arrested and ateretic follicles increased. The FBX during postbreeding phase had no such effect, whereas in 30 day ovariectomised (OvX) lizards in prebreeding phase fat body mass significantly increased but HSI decreased. However, in lizards in prebreeding phase, E2 caused a significant decrease in fat body mass and an increase in HSI, while during the postbreeding phase there was a significant increase in HSI but the fat bodies were not affected. The above findings suggest that the development of the first clutch of vitellogenic follicles in the lizard utilises lipids stored in the fat bodies and that the growth of the subsequent clutches of vitellogenic follicles is met through the intake of food, which is abundant in the latter part of the breeding phase. The fat bodies are not needed for the growth of previtellogenic follicles. The fact that lipolytic action of E2 occurs only during the breeding phase suggests that responsiveness of the fat bodies to the steroid is related to the reproductive phase and that during postbreeding phase of the lizard they become refractory to E2.     

Prevalence of adult ADHD in an all-female prison unit

There is increasing evidence suggesting a link between ADHD and criminality, including a strong association between ADHD symptoms and the likelihood of being on probation or in prison. Most studies investigating the prevalence of ADHD in prison populations have focused on adult male offenders. In the current study, 69 female prisoners were screened for both childhood and adult ADHD symptoms using the Barkley Adult ADHD Rating Scale-IV. The results indicate that 41 % of the prisoners met the diagnostic criteria for ADHD in childhood and continued to meet criteria for ADHD as adults. More importantly, young female prisoners (aged 18–25) were significantly more likely to report symptoms of ADHD than older prisoners. Prisoners who reported symptoms of ADHD also reported high levels of impairment associated with these symptoms. A better understanding of the prevalence of ADHD in female prison units can highlight specific areas for intervention during rehabilitation, as well as the management of serious incidents within prison.     

Anti-predator behaviour changes following an aggressive encounter in the lizard Tropidurus hispidus

Avoiding predators may conflict with territorial defence because a hiding territorial resident is unable to monitor its territory or defend it from conspecific intrusions. With persistent intruders, the presence of an intruder in the near past can indicate an increased probability of future intrusions. Therefore, following a conspecific-intrusion, territorial residents should minimize costs from future intrusions at the cost of higher predation risks. I conducted experiments with males of the territorial lizard Tropidurus hispidus recording approach distance (distance between predator and prey when the prey escapes) and time to re-emergence from a refuge after hiding. Past aggressive interactions affected anti-predator behaviour: lizards re-emerged sooner (compared to a control) when the predator attacked 5 min after an aggressive encounter. If the predator attacked while an aggressive encounter was ongoing, there was also a reduction in approach distance. The results are consistent with an economic hypothesis which predicts that T. hispidus incur greater predation risks to minimize future territorial intrusion; additionally they show that the effects of past and ongoing aggressive interactions are different, consistent with the minimization of present intrusion costs. These results are relevant for studies of the changes in aggressive behaviour due to changes in the social environment and for studies of the costs and (co) evolution of aggressive and anti-predator strategies.     

Neural control of male-like pseudocopulatory behavior in the all-female lizard, Cnemidophorus uniparens: effects of intracranial implantation of dihydrotestosterone

Dihydrotestosterone was implanted directly into the brain of ovariectomized all-female Cnemidophorus uniparens. Only implants located in the anterior hypothalamus-preoptic area (AH-POA) induced male-like pseudocopulatory behavior. Implants in other brain regions, including the ventromedial hypothalamus (VMH), failed to elicit mounting and intromission behavior. Implants in the VMH also failed to elicit female-like receptive behavior. Radioimmunoassay revealed no significant difference in circulating levels of androgen between the responding and the nonresponding animals. These findings support previous studies implicating the AH-POA as the major integrative area for male-typical mounting and intromission behavior.     

Cold entrainment of the annual cycle of ovarian activity in the lizard Lacerta vivipara: thermoperiodic rhythm versus hibernation.

A constant warm thermoperiod maintains ovarian quiescence in the lizard Lacerta vivipara, whereas a 4-month artificial hibernation rapidly induces synchronized vitellogenesis after transfer to warmth. The present study examined the possibility of a thermoperiodic regulation of the ovarian cycle and the formal properties of an internal temporal program. These questions were addressed using 24-hr thermoperiodic conditions that combined a long or a short thermophase (6 or 2 hr of basking) with a warm (19-21 degrees C), a cool (5-15 degrees C), or a cold (3-7 degrees C) cryophase. Lizards were exposed to the natural photocycle or to LD 12:12. Occurrence and timing of vitellogenesis completion were monitored using immunodetection of plasma vitellogenin and laparotomies. Cold remained stimulatory when given intermittently with a 24-hr periodicity. However, under long-thermophase conditions, lizards responded poorly to cool cryophases but fully to cold ones (72.7-100% vitellogenesis). Thus a certain amount of cold must be provided during each 24-hr cycle in order to be effective through the succession of thermocycles. Reduction of the daily heat input from 6 to 2 hr modulated the stimulating effects of cold cryophases: The median date for the beginning of vitellogenesis occurred 1 month earlier, but the number of responding females decreased from 100% to 40%. The thermoperiodic regulation of the ovarian cycle also relies upon a precise heat-cold balance per nycthemeral unit. This ensures the entrainment of an internal rhythm, since the timing of reproductive responses varies with the date of transfer from the inhibitory warm thermoperiod to the inducing thermoperiod (long thermophase, cold cryophase). At least half the females started vitellogenesis within 1-2 months after a late transfer (winter solstice) instead of 6 months after an early one (autumn equinox), and the median date for onset differed by 1 month between the two groups. However, autumn transfer was the only one to induce a group response in close agreement with the natural timing.     

Block of mitochondrial apoptotic pathways in lizard ovarian follicle cells as an adaptation to their nurse function

Pyriforms are ovarian follicle nurse cells that undergo apoptosis at the end of previtellogenesis and are completely eliminated by the epithelium. This event is accompanied by the active transfer of organelles and macromolecules to the oocyte via an intercellular bridge. Since it would be a nonsense for damaged mitochondria to reach the oocyte, we have postulated that pyriform cells have adapted their apoptotic machinery to prevent mitochondrial degradation. To verify this hypothesis, we have studied mitochondrial morphology and functionality during follicle cell regression. Cytological and biochemical evidence indicates that mitochondria in pyriforms maintain their size, organization and membrane potential. This clearly indicates that they are not involved in apoptosis signalling/progression. This block would favour both the oocyte, by increasing the pool of organelles available from follicle cells, and also the regressing pyriforms, by maintaining the energy resources required for completion of their nurse function. The block is probably attributable to an over-expression of Bcl-2 and might be carried out by sequestering cytochrome c inside the organelles. As demonstrated by in vitro experiments, the mitochondrial apoptosis pathway can be activated by stress induction, such as serum deprivation, but not following physiological pro-apoptotic signalling, such as treatment with gonadotrophin-releasing hormone. These studies were supported by a grant from the MIUR (PRIN project: Molecular responses of embryonic, differentiated and tumoral cells exposed to cadmium intoxication).     

Cell cycle and behaviour in Euplotes crassus: an attempt at describing the biological relationship between its cellular and organismic natures

The two-faced nature of protozoa allowed us to study the relationship between cell cycle and behaviour in Euplotes crassus; the former represents one of the most typical cellular traits, the latter is one of the most significant characteristics of an organism. Dividing cells of E. crassus were isolated on a slide and recorded for 11 h: the classic ethographic parameters were calculated every 60 min. The percentage of mobile cells went from 0-100% in the first 2.5 h. This value was maintained for 6.5 h, but from 9 h the value began to drop, reaching 0% at 11 h. The relative frequency of leftward arcs was very high in the first hour, the radius and length of the arcs increased from 1-7 h; velocity showed a similar trend, peaking at 7 h. All our results showed that the behaviour of this ciliate is heavily affected by its cell-division cycle.     

Male-like sexual behaviour of female rats with unilateral lesions in the hypothalamic ventromedial nuclear region.

In castrated female rats treated with androgen or oestrogen a significant decrease of female sexual behaviour assocated with a significant increase of male sexual behaviour was induced by unilateral lesions of the hypothalamic ventromedial nucleus.     

Embryonic behaviour in the lizard, Lacerta vivipara

The behaviour of embryos of the lizard Lacerta vivipara has been studied in cultured eggs, removed from the mother. Spontaneous movements begin at a time when the embryo is still unresponsive to touch, and about two days before the appearance of reflex responses. The earliest movements consist of lateral flexion which gradually gives place to dorsiventral flexion. Embryonic movements are not necessarily related to contractions of the amnion. The activity of the embryo, as measured by the number of times movements were initiated and the amount of time spent in activity during a half hour period, rises to a plateau and then decreases sharply as the time of hatching approaches. Activity of the tail is prominent, particularly at times when other movements occur in rapid succession. Serpentine movements were not observed in embryos younger than stage 39; some prematurely born animals showed such activity in response to contact with the substratum. During embryonic life any part of the animal may move individually or in combination with any other part, such combined movements being unco-ordinated. In these respects the spontaneous motility of the lizard embryo closely resembles that of the chick. Statistical analysis of the embryonic movements provides evidence of rhythmic activity within the developing central nervous system.     

The relationship between morphology, escape behaviour and microhabitat occupation in the lizard clade Liolaemus (Iguanidae: Tropidurinae: Liolaemini)

Phenotypic differences among species are known to have functional consequences that in turn allow species to use different habitats. However, the role of behaviour in this ecomorphological paradigm is not well defined. We investigated the relationship between morphology, ecology and escape behaviour among 25 species of the lizard clade Liolaemus in a phylogenetic framework. We demonstrate that the relationship between morphology and characteristics of habitat structure shows little or no association, consistent with a previous study on this group. However, a significant relationship was found between morphology and escape behaviour with the distance a lizard moved from a potential predator correlated with body width, axilla-groin length, and pelvis width. A significant relationship between escape behaviour and habitat structure occupation was found; lizards that occupied tree trunks and open ground ran longer distances from predators and were found greater distances from shelter. Behavioural strategies used by these lizards in open habitats appear to have made unnecessary the evolution of limb morphology that has occurred in other lizards from other clades that are found in open settings. Understanding differences in patterns of ecomorphological relationships among clades is an important component for studying adaptive diversification.     

Cell cycle regulators in bladder cancer: relationship to schistosomiasis

Dysregulation of cell cycle control may lead to genomic instability, neoplastic transformation and tumor progression. In terms of the particular roles in regulation of the cell-cycle, p21(WAF1) causes growth arrest through inhibition of cyclin-dependant kinases required for G1/S transition. P16 (INK4A) and p15 (INK4B) are thought to act as tumor suppressors, since their inactivation and/or deletion are observable in various types of malignancies. Cyclin D1 is hypothesized to control cell cycle progression through the G1-S check point. The present study evaluated p21 expression, p16 and p15 gene deletion and cylin D1 expression in bladder carcinoma among Egyptian patients, in relation to different clinicopathological features of the tumors and presence or absence of bilharziasis. Tissue specimens were obtained from 132 patients with bladder carcinoma and 50 normal tissue samples from the same patients served as control. P21 was determined by Western blot (WB) and enzyme immunoassay (EIA), p16 and p15 gene deletions were examined by polymerase chain reaction (PCR) and Cyclin D1 was detected by WB. Levels of p21 were lower in malignant tumors than in normal tissues. Lower expression of p21 was evident in lymph node positive, well differentiated tumors and squamous cell carcinoma (SCC) than in lymph node negative, poorly differentiated tumors and transitional cell carcinoma (TCC). In all normal samples, p15 and p16 genes were detected while cyclin D1 was not detected. P16 and p15 genes were deleted in 38.7% (41/106) and 30.2% (32/106) of bladder tumors respectively. The deletion of both genes was associated with poor differentiation grade and presence of bilharziasis. P16 deletion was also correlated to advancing tumor stage. Cyclin D1 was expressed in 57.5% of bladder tumors (69/120), where its expression was correlated to early stage, well differentiation grade, schistomiasis, and low levels of p21. Cell cycle is dysregulated in bladder carcinoma. This was evident from the increased expression of cyclin D1, the decreased levels of p21 and the deletion of p15 and p16 genes. Moreover, p16 and p15 gene deletion was related to tumor progression and might have a role in bilharzial bladder carcinogenesis. Cyclin D1 over-expression appears to be an early event in bladder cancer and might explain bilharzial associated bladder carcinogenesis.     

The circadian cycle: daily rhythms from behaviour to genes

The daily recurrence of activity and rest are so common as to seem trivial. However, they reflect a ubiquitous temporal programme called the circadian clock. In the absence of either anatomical clock structures or clock genes, the timing of sleep and wakefulness is disrupted. The complex nature of circadian behaviour is evident in the fact that phasing of the cycle during the day varies widely for individuals, resulting in extremes colloquially called 'larks' and 'owls'. These behavioural oscillations are mirrored in the levels of physiology and gene expression. Deciphering the underlying mechanisms will provide important insights into how the circadian clock affects health and disease.     

Isolation,characterization and molecular cloning of cathepsin D from lizard ovary: Changes in enzyme activity and mRNA expression throughout ovarian cycle

During vitellogenesis, the oocytes of oviparous species accumulate in the cytoplasm a large amount of proteic nutrients synthetized in the liver. Once incorporated into the oocytes, these nutrients, especially represented by vitellogenin (VTG) and very low‐density lipoprotein (VLDL), are cleaved into a characteristic set of polypeptides forming yolk platelets. We have studied the molecular mechanisms involved in yolk formation in a reptilian species Podarcis sicula, a lizard characterized by a seasonal reproductive cycle. Our results demonstrate the existence in the lizard ovary of an aspartic proteinase having a maximal activity at acidic pH and a molecular mass of 40 kDa. The full‐length aspartic proteinase cDNA produced from total RNA by RT‐PCR is 1,442 base pairs long and encodes a protein of 403 amino acids. A comparison of the proteic sequence with aspartic proteinases from various sources demonstrates that the lizard enzyme is a cathepsin D. Lizard ovarian cathepsin D activity is maximal in June, in coincidence with vitellogenesis and ovulation, and is especially abundant in vitellogenic follicles and in eggs. Ovarian cathepsin D activity can be enhanced during the resting period by treatment with FSH in vivo. Northern blot analysis shows that cathepsin D mRNA is exceedingly abundant during the reproductive period, and accumulates preferentially in previtellogenic oocytes. Mol. Reprod. Dev. 52:126–134, 1999. © 1999 Wiley‐Liss, Inc.     

Effects of group stability, male-male aggression, and male courtship behaviour on environmentally-induced ovarian recrudescence in the lizard Anolis carolinensis

Reproductively inactive, winter dormant female Anolis carolinensis were exposed to a stimulatory environmental regime while in socially stable or unstable male-female groups. In a second experiment, winter dormant females were exposed to varying amounts of male courtship and male-male aggression. Results indicate that (1) the presence of a stable dominance hierarchy among group males is necessary for male facilitation of environmentally-induced ovarian recrudescence (OR) (an unstable dominance hierarchy inhibits OR), (2) the behaviour patterns responsible for the facilitation and inhibition of environmentally-induced OR are courtship and male-male aggression, respectively, and (3) ovarian development is graded in accordance to the amount of male courtship to which the female is exposed. It is proposed that male courtship insures normal gonadotropin (GT) secretion while the absence of male courtship results in subnormal GT secretion and the presence of male-male aggression suppresses environmentally-induced GT secretions. The functional significance of the inhibition of environmentally-induced OR by male-male aggression and its possible relation to differential vernal emergence in temperate-zone reptiles is discussed.     

Copulatory behaviour of the lizard Anolis sagrei: alternation of hemipenis use

The pattern of use of the hemipenes, the two independently functioning intromittent organs of squamate reptiles, was investigated in the male brown anole, Anolis sagrei. Males demonstrated a significant tendency to use the left and right hemipenes alternately when mated daily for 7 days with different females. The duration of copulation differed significantly among males and was independent of the hemipenis used. Hemipenis use was also examined in two successive copulations separated by different time intervals. After an intercopulatory interval of up to 3 h, males showed a significant tendency to alternate in the use of their hemipenes. This trend was still present following an intercopulatory interval of 24–26 h, but was not detectable following an interval of 72–74 h. Thus, alternation of hemipenis use in male brown anoles declines as the interval between copulations increases, suggesting that males adjust their copulatory posture in relation to the length of the intercopulatory interval.     

Wolbachia infection and an all-female trait in Ostrinia orientalis and Ostrinia zaguliaevi

Sex ratio distortion toward females (SR trait), induced by a Wolbachia bacterium, has been reported in two species of the Ostrinia furnacalis group, viz., O. furnacalis, and O. scapulalis (Lepidoptera: Crambidae). In addition, an SR trait caused by abacterial, unidentified agent(s) is known in O. scapulalis. Here we examined the SR trait in four other species of the furnacalis group, viz., O. orientalis, O. zaguliaevi, and O. zealis from Japan, and O. nubilalis from central and eastern Europe. Wolbachia infection was detected in three O. orientalis females and in one O. zaguliaevi female, and the infection was always associated with the SR trait. In terms of wsp and ftsZ gene sequences, Wolbachia strains in O. orientalis and O. zaguliaevi were indistinguishable from each other, or from those in O. furnacalis and O. scapulalis. These findings suggest that Wolbachia strains in the four Ostrinia species are probably identical. In addition, one O. zealis female, which was negative in diagnostic PCRs for Wolbachia and general bacteria, produced an all‐female brood. This trait was very similar to the SR trait caused by abacterial agent(s) in O. scapulalis.