Head Appendages Research Articles

In vivo uptake and metabolism of testosterone by the head appendages of the cock

Two h after a 5-min subcutaneous infusion of 1, 2- 3H-testosterone to 24 h castrated cocks, the uptake and metabolism of the steroid was determined in the comb, the wattles, the ear lobes, the lungs and the breast muscles. The concentration of radioactivity by unit weight was the highest in the lungs and the wattles, then in the ear lobes and the comb. In the muscles, the radioactivity was slightly higher than in the plasma. The proportion of bound hormone in the supernatant was found to vary in each tissue. It was the highest in the lungs and the lowest in the muscles. In the supernatants, polar metabolites, including 5a-androstanediol, constituted an important part (more than 50%) of the total recovered radioactivity after thin layer chromatography. The supernatant bound steroids comprised about 80% of testosterone and dihydrotestosterone. The DHT/T ratio was high for the head appendages and lower in the lungs and the muscles.

Androgen binding proteins in cock's tissues: properties of ear lobe protein and determination of binding sites in head appendages and other tissues.

Specific dihydrotestosterone (DHT) binding was demonstrated in the ear lobe cytosol of the cock. The binding not influenced by the additionof 6 mM mercaptoethanol or 0.3M KC1 in the homogenization medium but it was decreased byEDTA 1.5 mM and Zn++ 1 mM. The addition of Mg++ or Ca++ in the incubation assay produced no visible effects at concentrations up to 5 mM while Zn++ decreased the binding at concentrations as lowas 10–6M. When present at a concentration of 1 mM, p-hydroxymercuribenzoate abolished the binding. The centrifugation speed used to prepare thecytosol also influenced the binding. There was less hormone bound in the 100,000 × g supernatant than in the 30,000 × g supernatant. The binding was abolished by pronase or trypsin treatment but not bythe other hydrolytic enzymes tested. The binding protein was found to be unstable at 37 C whether inthe presence or in the absence of hormone. It has ahigh affinity (Kd = 5.5 × 10−10M) and the number of binding sites is small (n = 3.31 pg/rng protein). It...

Head Appendage and Wing Cleaning in Blackflies (Diptera: Simuliidae)1

Behavioral patterns associated with cleaning of the wings and certain head appendages and the structures used were studied in Simulium venustum, S. rugglesi, S. euryadminiculum, S. aureum, S. baffinense , and S. arcticum . A patch of hairs and basitarsal comb on the metathoracic legs are used to clean the wings, while the proboscis, palps, and antennae are cleaned by a patch of hairs on the prothoracic legs. Different areas of the wings are cleaned using distinct procedures. Frequent wing combing upon emergence may aid in complete extension of the wings.

Comparative functional morphology of feeding in three species of caprellids (Crustacea, Amphipoda) from the northwestern Florida Gulf Coast

The functional morphology of feeding has been investigated in three species of caprellid amphipods. Feeding preferences are correlated with the increased setation and stoutness of the head appendages, the denser the setae the greater the trend toward filter-feeding. It was found that Caprella penantis Leach fed primarily by filter-feeding and scraping; Paracaprella tenuis Mayer relied on filter-feeding, scraping, scavenging, and predation; and Luconacia incerta Mayer depended almost entirely on predatory habits. The observed feeding patterns were verified by stomach content analysis.

Über die morphogenetische Wirkungsweise von Juvenilhormon und analogen Substanzen auf die Adultentwicklung von Schwärmern und Spinnern1,2

AbstractMorphogenetic effects of juvenile hormone and analogues on the development of Sphin‐gidae and Notodontidae. Treatment of larvae of Cenura vinula and Sphinx ligustri with juvenile hormone and analogues such as geraniol, an isomer mixture of farnesol, aethyl‐farnesoate‐dihydrochloride, and an isomer of C18 juvenile hormone, showed that the effect is dependent on the amount of the applicated compounds and on a critical time interval within the last larval instar. The inhibitory action of the used compounds on metamorphosis varies, the effect of farnesol was less extensive, that of geraniol more extensive than that of aethylfarnesoate‐dihydrochloride and of C18JH. Between the second and third day after the last larval molt there is a period of maximal sensitivity. The symptoms of the juvenile hormone‐like action of the four compounds were similar and were evidenced in a prolongation of the feeding period of the last instar, a prevention of some differentiation processes and a considerable delay of the larval‐pupal molt. High doses of the compounds resulted in giant larvae. Thereafter larval‐pupal intermediates were formed either with more larval or more pupal characteristics whereas the target tissues of the head and thoracal segments were more sensitive than the abdomen. Imagines of the experiments had defective head and thoracal appendages, reproductive system and pheromone glands, so that they were not able to mate. Some of them were laying eggs, the embryos of which were not able to hatch.

Anomalous Dimorphism in Aedes vexans1,2,3

This record is the 1st report of anomalous dimorphism in Aedes vexans (Meigen) (Diptera: Culicidae). Two specimens, each having a different embryogenic and filial background, were found in cultures originating from wildcaught females from Champaign County, I11. Both specimens exhibited dimorphic mixtures involving appendages of the head and internal organs of reproduction. The maxillary palpi of both specimens were reduced apically. One specimen exhibited a cercus, whereas the other specimen exhibited a reduction of the clasper. Reasons for occurrence of anomalous dimorphism in the specimens described are unknown, but the dimorphism may have resulted from high embryogenic temperatures, the presence of a genetic factor of low frequency, or both.

Fly Identification by the Morphology of the Head and Head Appendages

Abstract Ten fly species are identified by the morphology of the head and head appendages. Detailed descriptions and numerous drawings are used to identify the fly heads, antennal segments, and mouthparts. Fragment identification provides a basis for species identification.

Gonadal maldevelopment in a flock of Rhode Island Red fowls.

SUMMARY In nine fowls with intersexual characteristics from a single hatch of commercial Rhode Island Red pullets, the shanks and tibiae were of female size; plumage and macroscopic post-mortem findings suggested the female type, although two birds had a few masculine saddle feathers. All except one, which had an extensive gonadal tumour, had a single left gonad which was atypical. Behaviour was asexual, except for one animal with masculine aggressiveness. The head appendages were masculine in all cases. In eight of the nine birds the gonads consisted mostly of ovarian-type stroma in which were a few immature and atrophic tubules, some cords of luteal cells, and a few cystic follicles. Oogenesis and spermatogenesis were never seen. Granular medullary cells of the gonadal stroma were quantitatively a most important cellular element, and it is suggested that their secretions may have been of significance in the development of the secondary sexual characters of the birds. Lipids in the gonads were histochemically similar to those of the normal ovary. Gonadal tumours were present in two cases, one tumour being very large, but they did not modify the intersexual appearance and behaviour of the birds. In general histology they resembled human dysgerminomata, and it is suggested that their main cellular component was derived from the germinal epithelium and was similar in origin to the medullary cells. Compared with the gonads, negligible amounts of lipid were present in the tumours. The other gonads were not neoplastic, although they may have had that potentiality.

A study of sex drive of two strains of cockerels through three generations

A population of thirty cockerels belonging to six sire families was tested for mating frequency and differences between the families were found to exist. The highest and lowest scoring males were chosen to sire the F 1 generation. The sons of the high scoring males (H.S. males) scored higher frequencies for mating activity than the sons of low scoring males (L.S. males). Furthermore, the H.S. males adapted themselves to females in a significantly shorter time than the L.S. males. An F 2 generation of H.S. and L.S. males was bred following the same programme as that for obtaining the F 1 males. Half the males from each strain were allowed access to young females from an early age, but this treatment did not affect the differences in mating frequency between the two strains; the H.S. males were superior to the L.S. males regardless of early experience. In the P 1 and F 2 generations an inverse relationship between the size of the head appendages and mating frequency was observed. No measurements were taken in the F 1 generation. The F 2 males were subjected to a number of physiological tests which were capable of indirectly discerning any large differences in the endocrinal output of the birds. No such differences were apparent. The birds were also examined in a number of other behavioural traits, but mating frequency appears to be the major behavioural difference between the two groups. The L.S. males in the F 2 generation were better semen donors than the H.S. males, and this was also found in an F 3 generation. In this last generation it was found that the H.S. males had more intromissions per ejaculate than the L.S. males. The significance of this finding is discussed.

THE RELATION BETWEEN OLFACTORY RESPONSE AND RECEPTOR POPULATION IN THE BLOWFLY

1. Measurements have been made of thresholds of rejection of two concentrations of pentanol vapor by normal blowflies and those from which various head appendages have been removed. The concentrations selected were 5.0 x 10-6M pentanol, to which 90% of the population normally responds, and 1.6 x 10-6M, to which approximately 25% of the population normally responds.2. The results show that the response elicited depends upon stimulation of specialized receptors present on the antennae and palpi and hence cannot be attributed to the action of a common chemical sense. Repellents in the gas phase undoubtedly act as olfactory stimuli. Different receptor fields function at different levels of sensitivity. The antennae are the most sensitive and the various mouth-parts less so. There is also a relation between threshold and the number of receptors functioning. Insects possessing both antennae respond to lower concentrations of odor than those bearing only one. This indicates that the two sides of the body are acting in concert. Whether it represents true neural contralateral summation or is based upon statistical bias cannot yet be decided with certainty although the data strongly suggest the latter. In either case, from the point of view of coordinated behavior it illustrates the manner in which bilaterally placed receptor fields may operate as a unit.

Experimental Data on the Function of the Interstitium of the Gonads: Experiments with Cockerels

1. The relative volumes of the testes and their components of 31 cockerels, 2-200 days old, were calculated and compared with the size of their increasing head appendages (Text-figs. 1a-d, 2); in addition, the effect of gestyl-administration on testes of cockerels of this age was investigated. 2. Several types of interstitial testis-cells could be distinguished morphologically and physiologically (Text-figs. 3-6 and Pl. 1); these cell-types were studied with different techniques and counted separately. 3. The main types of the interstitial cells are: (a) Lipoid cells, totally packed with lipoid globules. These cells, which are considered by many authors as fully developed Leydig cells, are not directly connected with the production of the male sex hormone; perhaps they have a secondary function in this respect, as cholesterolderivatives are stored in these cells (Pl. 1, Text-fig. 3a). (b) Secretory cells, characterized by the absence of lipoid vacuoles and the presence of numerous granular and filamentous mitochondria. These secretory cells, which produce the male sex hormone, can be divided into secretory cells A (Text-fig. 6a) without, and secretory cells B with, one large vacuole (Text-figs. 6b, 6c, 6d). 4. A considerable and partly intercellular storage of lipoids may take place at any age in the intertubular connective tissue (Text-figs. 3-4 and Pl. 1). 5. The number of the lipoid cells depends on the nutritive conditions of the animal and the development of its testes (Text-fig. 7). 6. In older cockerels most of the glandular cells lose their secretory function and pass over into lipoid storing cells. 7. Therefore we agree with Benoit, when he denies the occurrence of a ‘secretion de luxe’, but we cannot accept the presence of a ‘parenchyme de luxe’ in the testes of older cockerels.

The Effect of Comb and Wattle Removal Upon Testicular Activity in the Domestic Fowl

DURING the past decade evidence has been accumulating that there is a relation between comb and wattle size and testis weight and that the removal of the head appendages may influence both body and gonad weights. Little information, however, is available concerning comb and wattle removal and testis function. If testis size is increased following dubbing it would seem logical to expect some changes in testis activity. The objectives of this experiment, therefore, were to determine the effects of dubbing upon semen production, as well as testis size and histology.Various workers, including Buckner, Insko, and Martin (1933), Parhon and Coban (1934), Zawadowsky (1935–1935a), Zawadowsky and Slavine (1935), and Marlow and Payne (1940) have reported an increase in testis weight following dubbing. Hoskins and Koch (1939) found that in only one of five trials did dubbing increase testis weight and that in this case, body weight was likewise increased. .

EXPERIMENTS CONCERNING SUPPOSED INFLUENCE OF COCICS HEAD APPENDAGES ON SIZE OF TESTES

IT is A WELL-KNOWN FACT that growth of the cock’s head appendages, comb and wattles, is under control of the testicular incretion. It was unexpected, however, when Buckner, Insko and Martin (1) and Zawadowsky (2, 3) independently reported that a relationship of opposite nature also exists, that is, that growth of the testes is influenced by removal of comb and wattles. Such a reciprocal effect, if verified, would be of considerable theoretical, perhaps even of applied, interest. It is not surprising, therefore, that several investigators set out to check the correctness of these results. The data, as they exist in the literature to date, are briefly summarised in table 1. Buckner, Insko and Martin (1) removed the comb from cockerels at the age of 4 weeks and killed the animals when they were 10 weeks old.

Studies on the Muscles of the Head, Neck, and Pectoral Appendages of Geomys Bursarius

Studies on the Muscles of the Head, Neck, and Pectoral Appendages of Geomys Bursarius Get access Edwaed Eugene Orcutt Edwaed Eugene Orcutt Underwood High School, Omaha, Nebraska Search for other works by this author on: Oxford Academic Google Scholar Journal of Mammalogy, Volume 21, Issue 1, 14 February 1940, Pages 37–52, https://doi.org/10.2307/1374656 Published: 14 February 1940

The Influence of Certain Methods of Management on Egg Production: I. Their Influence on Winter Egg Production

Considerable time and effort has been spent by various students of egg production in attempting to influence the number of eggs laid by changing the methods of feeding or of managing the birds in various ways. Out of it have come certain practices now regarded as standard. More recently it has been shown that production can be increased through artificial illumination and extra feeding during the season of short days. The feeding of milk has been followed in some experiments by increased annual production. On the other hand, it is known that Leghorns are adversely influenced by cold weather as compared with the American breeds, possibly because of the large highly vascular naked head appendages which may have a surface area in some instances of at least 17 square inches, and thus conceivably may act like the radiator of an automobile. The amount of heat lost through these appendages is .

The Evolution of Arthropods and Their Relatives with Especial Reference to Insects

The points which should be especially emphasized in regard to the evolution of the insectan branch of the arthropod lines of development may be briefly summarized as follows: The ancestors of arthropods were not of any one type, but varied in regard to the number of segments composing their bodies, the outline of the body, etc.; and while some of them may have been as small as the tardigrades, it is more probable that the types would be included between the extremes represented by the Onyohophora and the Annelida, or even between the extremes included within the annelidan group itself. The first arthropods also were not of one single type, but possibly varied as greatly among themselves as a branchiopod-like copepod would differ from a copepod-like branchiopod, etc. It is very probable that the stem forms eventually giving rise to the line of development leading up to the production of the insectan type of arthropod would be included in the branchiopod group. The next stage in the evolution of the insecta...