Get an Invitation. Notes: Imported from Wattpad same. Work Text: Patti was irritable and tired as she and Terri got home. That talent is pretty limited, and don't even get me started on Franci or Janet" "I thought we all did pretty good" Terri replied with a small smile. The rest was a disaster" "You need rest" Terri observed softly, gaining a small chuckle from the director.
Post Comment Note: All fields are required. Author : Nicholas J. This work was reproduced from the original artifact, and remains as true to the original work as possible.
Therefore, you will see the original copyright references, library stamps as most of these works have been housed in our most important libraries around the world , and other notations in the work. The testes of Cnemidophorous lizards are char- Among amphibia, two types of testicular acterized by the presence of a compact layer of cycle have been recognized by Van Oordt Leydig cells or circumtesticular cells between : continuous and discontinuous. The the tunica albuginea and the seminiferous tu- latter type is represented by Rana temporaria.
By summer, a large number of germinal cysts have been formed in which sperm mature by the fall months.
Primary spermatogonia are refractory follows a short, intense courtship period. In to gonadotropin stimulation in midsummer, these animals, stem spermatogonia do not when temperatures are still high. Van Oordt populate permanently the structures in which distinguishes between potentially dis- spermatogenesis occurs.
Spermatogenic cysts continuous and truly discontinuous breeders. In form anew at each breeding season in conjunc- the former, primary spermatogonia never be- tion with the divisions of a single stem cell.
In some subtropi- Leblond, , possibly providing for a greater cal species Rana esculenta, Discoglossus pictus number of sperm at one time for what is the spermatogenic cycle is continuous except in generally external fertilization.
In amniotes, the the northerly part of their range, where lower spermatogenetic cystic type has been super- temperatures in winter cause discontinuity. In seded by the seminiferous tubule, a permanent Rana esculenta, experimental exposure to high- structure lined with stem cells. Waves of sper- er temperatures during the normal regressing matogenesis arise periodically within this mor- stage can stimulate spermatogenic potential phologically distinct epithelium.
Galgano, In many seasonally breeding warm-blooded Readily recognizable interstitial cell cycles animals, spermatogenesis occurs in the spring are seen and documented in anuran amphibia. After spawning, a tion, the lobules in any particular zone being marked increase in cholesterol-rich lipid con- packed with cysts in an identical developmental tent occurs concomitant with a decrease in stage.
In some species, the zonation is oriented 3j3-HSD. During the period six weeks post- cephalo-caudally so that in longitudinal section nuptial, the lipids gradually disappear from the one can see a succession with the least advanced Leydig cells which regress and cannot be lobules anteriorly and the most advanced cau- distinguished from connective tissue cells.
In the multiple type gonad this sequence This interstitial cell cycle is basically similar is seen in each lobe. Th testicular area occu- to that of other seasonally breeding vertebrates. Thus, in Triturus R. This cycle of tids, while the other zones are restricted. This the anuran is basically similar to that described distinction may be easily discernible with the for the cobra by Lofts As spermatozoa are released, the In anurans, Sertoli cells form from follicle progression is caudo-cephalic and, by February, cells of the germinal cysts as in elasmobranchs most of the lobules are evacuated.
Immediately Fratini, ; Simpson and Wardle, and preceding sperm discharge, the lobule walls teleosts Lofts, ; Wiebe, , As the glandular waxing and waning of cholesterol rich lipoidal tissue degenerates and is reabsorbed, spermato- material. As the breeding season approaches, genesis begins again, the testicular lobes expand cells become more glandular in appearance and the proliferation of small lipid droplets occurs in the cytoplasm which begins to show 3j3-HSD and glucosephosphate dehydrogenase activity 5,oqi A B C D E F S H I J S L Van elongate Oordt prior and Brands, to actual sperm At this time, they are rich in cholesterol and negative for HSD.
As the tubule collapses, the Sertoli cells are compressed so that the lumina appear to be filled with a mass of cholesterol rich lipid. A similar cycle has been S observed in R. The anuran postnuptial tubules remain in this state for several months and as in birds, Marshall, , reptiles Lofts et al. Seasonal changes in testicular weight and matogenesis. From the old Sertoli cells have disappeared. Tso and Lofts a. The source of steroid hormones in urodeles is of great interest.
The glandular tissue de- Reptiles scribed above has been demonstrated to possess Among the squamate reptiles, at least five 3-HSD in a variety of urodele species Lofts, different types of testicular cycles may be and displays ultrastructural characteris- observed Licht, b.
Cycles vary from tics of steroidogenic tissue Picheral, , species in which spermatogenesis and Leydig Precise location of the steroidogenic cells, Seamark, , to chelonian species in which however, is still controversial since according to temporal separation of these testicular func- the current interpretation of structural studies tions is quite clear Lofts, , ; Callard this glandular tissue has two components, the et aI.
Regarding the role of transformed Sertoli cells and the hypertropic androgens in the control of spermatogenesis, connective tissue cells of the lobule walls Tso the latter type of cycle is particularly interest- and Lofts, b. The contribution of these ing since both histological and histochemical two tissues varies from species to species and it indices Lofts, and plasma testosterone has been suggested in the older literature that levels Callard et al.
Lofts and coworkers have de- chemistry have demonstrated HSD activity scribed seasonal cycles of Leydig cell and in the cells of the lobule walls Lazard, , Sertoli cell activity in a squamate and a turtle, which also have ultrastructural characteristics which represent synchronous and asynchron- of steroid secreting elements, resemble anuran ous types as far as spermatogenesis and Ley- Leydig cells and may be homologous with them dig cell functions are concerned.
Thus, in the Lofts, Although little information is turtle, Trionyx sinensis Lofts and Tsui, , available on these cells in urodeles, they have during the March-April breeding season, Leydig been extensively studied in fish where they are cells are large and lipid free and show positive known as lobule boundary cells LBC Mar- 3i3-HSD correlated with a highly developed shall and Lofts, ; Lofts and Marshall, epididymis, regressed seminiferous tubules with ; Lofts, ; Lofts and Bern, ; Grier densely lipoidal material.
At this time mating and Linton, According to Tso and Lofts and fertilization is achieved by discharge of b , the LBC in urodeles is similar to that sperm stored in the epididymal canals. Immedi- of the anuran Leydig cells. In mature lobules, after germ cell evacuation, the cells which line the periphery of the cyst are enlarged, depleted of lipid and have a strong HSD reaction. In the glandular tissue, loss of lipid continues, E contrasting sharply with Sertoli cells which are at this time densely laden with lipid.
A positive 3j3-HSD from a , is September but present this to reaction in Triturus January is not Tso hongkongensis present and Lofts, in the j Sertoli Sertoli cells of cells show the same a histochemical lobule.
Thus, cycle the of lipid I depletion and repletion similar to that of the Leydig cells, but somewhat in advance of the latter Lofts, Both the ultrastructural FIG. Generalized cycle of seasonally breeding male turtle. Lofts and Tsui observed 3j3-HSD lipid.
Spermatogenesis continues until early and HSD activity in Trionyx tubules in autumn. We have Lofts suggested that rapid depletion previously noted 3j3-HSD in the seminiferous of cholesterol rich lipid from the interstitium epithelium Sertoli cells of the snake, Natrix was possibly indicative of increased androgen Callard, and Lofts made similar synthesis, as supported by the condition of the observations in the cobra, Naja naja.
Further, epididymis. A recent study from this laboratory microdissected seminiferous tubules of this Callard et al. In Trionyx, the picta, with the testicular cycle and demon- and HSD activity of the tubules at the strated that high plasma testosterone Fig. As a suggest Sertoli cells may be the loci of steroido- negative corollary of this, activity of the germi- genesis. Recently, we Lance et al.
This and this is also true of reptiles Lofts and suggests that when stimulated, tubular elements Chiu, In the chelonians described above, may contribute to peripheral androgen. How- assuming that spermatogenesis is an androgen ever, it would appear in Chrysemys at least, dependent process Steinberger, , a tubu- since plasma androgen remains low during the lar source of androgen or other steroid having summer when spermatogenesis is proceeding, spermatokinetic activity must be sought.
This is that tubular androgen does not reach the substantive evidence that in both mammalian peripheral circulation in significant amounts. In fish, andro- o gens stimulate regressed testes in hypophysec- o tomized animals and cause an increase in testicular size and spermatogenesis. Thus, in h y p0 physectomized Fundulus heteroclitus, Pickford and Atz noted an increase in testicular size following androgen injections.
IoO Stimulation of spermatogenesis was seen after 4. Spermatogonial prolifera- 01 tion can still proceed in some fish in the absence of the pituitary gland Barr, ; 0 0 Lofts et al. Eversole reported that 8 testosterone propionate hastens germ cell ma- 00 o0 turation in Lebistes, a suggestion supported by 01 0 more recent work reviewed by Dodd Plasma testosterone values throughout the year in male Chrysemys picta.
From Callard et al. Sundararaj and Nayyar, Plasma testosterone in male Chiysemys picta following single injections of mammalian FSH. From Lance et al. In amphibia, the picture is confusing since Most of the observed inhibitory responses both stimulatory and inhibitory actions of probably result from suppression of gonado- androgen have been observed Lofts, Response of Ch,ysemys picta to single injections of avian gonadotropins.
Androgens androgen induced testicular atrophy Cci and were tentatively identified in the plasma of Acosta, ; Cci et a!. In a recent paper, Raja radiata and R. Using radioim- mized Ambystoma tigrinum larvae depending munoassay RIA , Dobson quoted by Dodd, upon the testicular status at the time. Rastogi has measured testosterone in the plasma et al. Even less information is available regarding Compared to other piscine groups, teleoste- testosterone effects on spermatogenesis in rep- an testicular steroidogenesis has received con- tiles.
Gorbman was unable to stimulate siderable attention. Thus, there is histochemical spermatogenesis by injections of 5 mg of and ultrastructural evidence for steroid secre- testosterone given over a period of 2 weeks in tion by the lobule boundary cells Yaron, ; Sceloporus occidentalis.
A spermatokinetic effect was us, ; Horstmann and Breucker, and observed at the spermatogonial stage and testos- the Sertoli cells Wiebe, ; Billiard, In all active steroid precursors Gottfried, ; Nan- hypophysectomized animals, primary spermato- di, ; Chester-Jones et al. In , extracts of Lampetra Parkinson, unpublished; Idler et al. Several in vitro studies have extracts of testis tissue from Scyliorhinus stel- identified 1 1-ketotestosterone and 1 1-hydroxy- laris Chieffi and Lupo, Simpson et al.
Saidapur and U Nadkarni, , ; Pesonen and Rapola, ; Biswas, , the lobule boundary cells in urodeles Certain et al. Ultrastructural studies on the lobule boundary cells Picheral, , ; Tso and Lofts, b and the interstitial cells of frogs Brok- 0. Seasonal changes in plasma steroids in the male plaice, Pleuronectes platessa.
Redrawn from gens. Eleven-ketotestosterone ters. However, the role of androgens in amphib- has been shown to have 10 times the potency ian spermatogenesis is still controversial Moore, of testosterone in promoting the appearance of ; Rastogi et al. In the latter species, however, Dorfman, ; Rao et al. The authors ; Ozon and Stocker, ; Gavaud, DHT has not detectable in immature animals and with the been identified in similar studies on testes of onset of maturation, levels rose sharply to lie urodele.
If this observation holds true for levels of testosterone and possibly testicular other urodele species and it can be demon- production of 1 1-ketotestosterone and the lat- strated that urodeles but not anurans do indeed ter, having lower plasma testosterone levels secrete these androgens, it might indicate, as is more similar to those of mammals.
As in mammals and birds, the interstitial ma of Necturus maculosus Rivarola et al. Sertoli cells generally give a nega- are far higher than tfose found in the Anura tive or weak reaction for 3j3-HSD, but Lofts and range 0. We have found a similar Tsui have shown that the presence of difference in the range of values in Bujo this enzyme, as demonstrated by histochemical marinus 0.
Highest levels occur during the Fig. Muller found DHT levels con- 20 - V siderably higher than those of testosterone in a 0 small sample of frogs with spermatogenetically -f4 0 4- active testes, but in a sample taken at another 10 7- I time of the year, testosterone was higher than 0 DHT. Wada et a!. Seasonal changes in plasma hydroxy- siderable differences in testes structure and steroids androgens in the lizard, Tiliqua rugosa. The former show the more teleost- From Bourne and Seamark Tsui and Licht, It has been suggested by Tsuneki et a!.
Acetone , however, that the seasonally breeding dried extracts of Myxine pituitary glands had F. Although the Myxine pituitary of the neurohypophysis. Further investigation contains PAS positive cells which were tenta- of this species is of the utmost importance. If tively identified as gonadotropes Fernholm this myxinoid can be shown to possess pituitary and Olssen, , these cells were unaffected gonadotropin s , it may help to determine by gonadectomy or steroid injection and whether or not the deep water forms are showed no morphological changes correlating degenerate and have lost pituitary regulation of with the functional stage of the gonads Fern- reproduction and also that a functional pitui- holm and Olssen, Matty et al.
The animals did not feed, but plant experiments in lampreys Dodd, a, appeared healthy and the females continued to ; Larsen, , ; Larsen and Roth- ovulate regardless of whether operated or in- well, ; Hardisty, and, in general, the tact. The authors also measured testosterone results are in agreement. Hypophysectomy pre- and estradiolL3 in the plasma by radioim- vents the appearance of the secondary sex munoassay and found similar levels in both characteristics and spermiation, but has only a sexes.
The level of testosterone in females delaying effect on spermatogenesis. Hypophysectomy or neural input. In all of these experiments, multiple s. If the operations are levels or ovulation. There was a suggestion of performed during the latter half of the sexual some testicular disorganization in a number of maturation stage they often have no effect the hypophysectomized hagfish, but in most Larsen, , suggesting that the pituitary cases spermatogenesis appeared to be proceed- hormones are necessary for initiating sexual ing normally.
These results would suggest that maturation and steroidogenesis, but that once there is little or no pituitary control over these processes are underway, they require little gonadal function in this species and that game- further gonadotropic regulation. However, there is no in- the study of pituitary control of reproduction formation on sexual maturation in this species, because of the unusual morphology of the which may be under pituitary control since the adenohypophysis Ball and Baker, Dodd PAS positive cells putative gonadotropes that et a!.
Mellinger reported neural connection with the hypothalamus, the identical results on removal of the ventral lobe elasmobranchs appear to follow the general from female Torpedo marmorata. Further in- vertebrate pattern in the hormones produced direct evidence of this segregation of the by the gonads and their roles in reproduction.
A specific reaction, observed only in the the effects of gonadotropins on gonadal ster- ventral lobe, could be blocked by excess unla- oidogenesis and circulating steroid levels in belled ovine LH.
Scanes et al. The significant cross reaction and that parallel dose nature of piscine gonadotropins, however, re- response curves could be generated with in- mains in dispute and it is in this area that some creased concentrations. However, using a more sensitive induce ovulation in hypophysectomized newts.
This assay, which uses the al. This gonadotropin has since been Xenopus oocyte meiosis as an end point, is shown to maintain spermatogenesis and induce relatively specific for mammalian LH, whereas spermiation in hypophysectomized males in a the 32P uptake assay measures both FSH and number of teleost species Donaldson, LH activity. However, there is activity in the ventral lobe and none in the now some doubt regarding the homogeneity of median lobe because they were measuring total this salmon gonadotropin as the SG frac- gonadotropin, whereas in their assay they were tion of Donaldson et al.
A further tion procedures. Burzawa-Gerard of Scyliorhinus canicula. The authors tentative- has also been able to demonstrate only a single ly identified 6 cell types based on granule size. A single glycopro- gonadotropes.
The pituitaries of 2 additional shown that, in some species at least, there is teleost species Salmo gairdnerii Breton et al. Similar reservations and also from all of the other fish gonado- have been expressed by Reinboth These biochemical Further data on the existence of more than results give further support to the concept of a 1 gonadotropin in fishes comes from 3 separate narrow species specificity within the teleosts as studies in which teleost pituitaries have been noted by Clemens and Johnson in their separated into various fractions by electro- study on the goldfish testis hydration factor in phoresis and column chromatography.
Two of the fractions The chemical nature of the fish gonado- 3 and 4 showed considerable gonadotropic tropins suggests a close similarity to mammalian activity when tested by the fish spermiation FSH and LU both in amino acid composition assay of Yamazaki and Donaldson Burzawa-Gerard However, information on the species used for was able to dissociate carp GTH into 2 bioassay and the magnitude of the response was distinct subunits, neither of which retained not given.
Idler et a!. What is of even greater importance is the tuitary glands which exhibited distinct physio- ability of the carp gonadotropin subunits to chemical behavior in the separatory system form hybrid gonadotropins upon association used.
Both fractions stimulated increased cAMP with subunits from other species. Burzawa- formation in immature trout gonads in vitro, a Gerard and Fontaine formed a hybrid bioassay in which mammalian hormones are molecule composed of the alpha subunit of inactive.
Fraction I was able to induce to propose that teleosts possess only 1 spermatogenesis and spermiogenesis and stimu- gonadotropin which combines the functions of late the Leydig cells, whereas the other fraction FSH and LU. When the fractions were tested on their studies of teleost pituitary glands. Van Oordt and de Kort , how- protein fraction from the same pituitaries was ever, argued that the cyclical changes in frog stimulatory.
This is in contrast to the situation testis could be explained on the basis of a single in amphibians Redshaw, and reptiles gonadotropin with a seasonal temperature-de- Neaves, where gonadotropins are re- pendent variation in tissue sensitivity. Thus, at quired for the uptake of vitellogenin by the low ambient temperatures, the Leydig cells and oocyte. Furthermore, in a recent comprehensive between gonadotropin and prolactin secretion review of the literature on the amphibian by the pituitary Reinboth, There is now biochemical evidence to the nature of the gonadotropins.
Lofts that amphibians probably do possess 2 gonado- showed that injections of mammalian tropins. Two fractions showing chemical simi- FSH and LU into hypophysectomized frogs larities to mammalian LH and FSU have recent- appeared to stimulate specific cell types within ly been isolated from pituitary glands of the the testis. Spermiation was induced and Leydig bull frog, Rana catesbeiana Licht and Papkoff, cells hypertrophied following LH injections, a; Papkoff et a!.
FSH fractions showed significant activi- Leydig cells. Identical results reported to be specific for mammalian FSH were obtained in a urodele amphibian by Licht and Papkoff, b. Two distinct bio- Andrieux et a!. In the latter bioassay stimulate glandular lobule boundary cell tis- method of Simon and Reinboth , one of sue. Using the same purification and separa- gonadotropins mFSH, mLH , however, have tion procedures, however, the authors could generally been ambiguous as to the specificity demonstrate only 1 biologically active fraction of the amphibian response to either LH or FSH in the pituitary of the urodele, Triturus crista- and have not helped clarify the problem of the tus, using 32P uptake by the testis of the same number of amphibian gonadotropins Barr, species as a bioassay.
The purified Rana go- In the frog spermiation test, highly nadotropins of Papkoff et a!. Muller both in vivo and in vitro. It would seem from these activity in these tests Fig. Bolaffi and Callard unpublished have definite conclusions regarding the role of FSH. There is a marked increase in circulating androgen 2 h after a single 5 jig injection of purified ovine LH LERA and a return to baseline levels after about 24 h Fig.
However, o DHT when estradiol was assayed it was seen that an 01 increase occurred 24 h after a single 2 jig injection of FSH, whereas the LH injected animals showed a less marked increase Fig.
Solid and open squares represent DHT ug ug and solid and open circles testosterone. The upper figure represents the changes in circulating androgens FIG. In vivo steroidogenic response of Necturus after a single injection of Rana gonadotropin. Blood to single intravenous injection of purified 0-FSI-I or samples were taken by heart puncture.
The lower 0-LH. Animals were bled at 0, 2 and 24 h. Open bars represent response at 2 h; solid bars addition of Rana gonadotropin. Redrawn from Muller represent response at 24 h.
Bolaffi a, b. The pituitaries of all squamates tested to a C25 - date on this bioassay are totally devoid of w 24 activity Licht, c. In vivo steroidogenic response of Nec- turus to single intravenous injection of purified 0-FSH I b. Open bars represent response at 24 h; shaded bars lack of LH from squamates is based on an assay represent response at 2 h n 5 at each dose.
Bolaffi and Callard, unpublished. The dispersed cell system of Cal! In all experiments, to date, it specific to urodeles. Although these data are has been shown to have a narrow specificity for preliminary, they might indicate that amphibi- mammalian FSH; LH from 3 mammalian spe- an interstitial or lobule boundary cells re- cies is biologically inactive except at doses spond to LH as do mammalian Leydig cells by where cross-contamination with FSH cannot be secreting testosterone and DHT and that the ruled out.
This system is responsive to gonado- urodele testis responds to FSH by increasing tropic activity in microgram amounts of ho- the aromatization of testosterone, as do the mogenized pituitary from a wide range of Sertoli cells of immature rats in vitro Fritz et species, except for snake Natrix pituitary a!. The response to avian tenable, since 2 separate molecules, similar in LH does not appear to be due to FSH contami- chemical characteristics to mammalian FSH and nation, since the response to LH can be LH, have been identified in 2 species of turtle inhibited by avian antiserum Callard and Ryan, and the alligator, though it is still argued that ; Fig.
Theseus finds them and then declares them to be married at his wedding. Later at the wedding, a play is performed and the wedded couples enjoy themselves while eating dinner and drinking. The other actors see him and flee right away. Bottom is left in the woods by himself. He stumbles upon Titania, the fairy queen. He wakes her, not knowing she had the love potion on her eyes. She awakes and immediately falls head over heels in love with him.
She treats him like a god. After this, Puck heads back to Oberon and tells him the juicy details. Oberon laughs, for he knows he won the little quarrel between him and his wife. He then goes to Titania after Puck reverses the potion. They get along and start dancing. While this happens, Bottom heads back to town and finds the actors.
They are to see he has returned to normal in time for the play. It was performed very badly and everyone started laughing. Everything was back to normal.
0コメント