Integumentary Glands Research Articles

The functional morphology of the brood sac in two species of ovoviviparous cockroaches,Byrsotria fumigata(Guerin) andGromphadorhina portentosa(Schaum). 2. Transmission electron microscopy

Summary Ultrastructural examination of the brood sac papillae in the ovoviviparous cockroaches Byrsotria fumigata and Gromphadorhina portentosa has revealed the presence of glandular units typical of the integumentary glands of many insects. Each unit includes a duct which originates within a large columnar secretory cell and passes through a duct or canal cell before opening at a pore on the cuticularised apex of a papilla. The structure of the glandular units from virgin and pregnant animals is described. Comparison of the ultrastructure of these brood sacs with that of the viviparous Diploptera punctata enables the ovoviviparous status of B. fumigata and G. portentonsa to be questioned.

Specialized integumentary glands of house rat,Rattus rattus

Specialized integumentary glands have been observed at certain specific body regions of the common house rat,Rattus rattus. Diverse zones such as eyelid, oral angle, prepuce and circum anal possess hypertrophied skin glands. The histophysiological aspects of these integumentary glands are reported. These specialized sebaceous glands have specific behavioural relevance.

Role of progesterone on the control of scent marking in Suncus murinus viridescens (Blyth)

The effect of castration and administration of progesterone in different doses on the specialized integumentary glands and scent marking behavior in male musk shrew, Suncus murinus viridescens were studied. Castration effected a considerable atrophy of the secretory epithelial tissues of the flank, oral lip and perineal glands with marked regression in their secretory output. Further, the scent marking frequencies were also reduced and attained a minimum level by the end of 4 weeks after castration. Progesterone administration in effective doses reactivated all these specialized integumentary glands and the scent marking frequency in male shrews within a period of three weeks.

Histology of a Sexually Dimorphic Integumentary Gland in Macroglossus lagochilus (Chiroptera: Pteropodidae)

A sexually dimorphic integumentary gland is described in the pteropodid bat, Macroglossus lagochilus . This gland is restricted to males from Central Province (mainland), Papua New Guinea and is not found in either males or females taken from the Bismarck Islands (Manus, New Britain, New Ireland, Duke of York). Histological examination of the glandular structure, which is readily identified externally as a crescent-shaped welt occupying the lower neck and upper chest, reveals that it is comprised of numerous hypertrophied tubular apocrine-type glands. Comparisons of the integumentary gland of Macroglossus males with those of other pteropodids that have been reported in the literature document striking differences in the organization and histology of sexually dimorphic glandular structures in Pteropodidae. The absence of the Macroglossus chest gland in individuals from the Bismarck Islands is not related to reproductive seasonality or to any apparent biological features of island and mainland populations.

Integumental glands associated with tactile hairs on the ovipositor of tephritid flies

The seventh abdominal segment, which forms the oviscape of the ovipositor in the tephritid flies Urophora affinis and U. quadrifasciata, bears setae in two bilaterally symmetrical rows on the dorsal and ventral aspects of its distal margin and scattered irregularly over the rest of its surface. At the anterior side of the base of each hair is a porous plaque covering a channel through the cuticle into which strands of a microtubular "secretory". material extend from the cytoplasm of a greatly enlarged gland cell. One such cell is associated with each hair, which is innervated by a single dendrite that terminates in a tubular body at the base of the hair. These gland cells are absent in male flies. The possible morphologic, functional, and taxonomic significances of these gland cells are discussed.

A study on olfactory communication signals in sambar deer,Cervus unicolor

The olfactory communication signals in eleven individuals of sambar deer were studied. They marked the objects in the enclosure with the secretions of diverse specialized integumentary glands. The tendency to sniff the marked sites was more consistent among females than in males. Both sexes of this species of deer depend considerably on olfactory cues during various social interactions.

Glandular Functions of Avian Integument

This paper attempts a synthesis of available information on glandular functions of avian integument, a topic which has not received adequate attention. Morphologi cally distinct glands in the skin of birds are limited to the uropygial gland, ceruminous (wax) glands in external ear canal and integumentary glands of the vent (anal glands). Of these, only the uropygial gland has been studied in a considerable manner., whereas taxonomic and functional status of the latter two remain unclear at the present juncture. The holocrine ceruminous glands, though lipoid producing, differ greatly from the uropygial gland in structure and functions. The glands of the vent are the only mucoid producing glands found in avian skin. Thus the avian integument, on gross examination, appears to be poorly endowed with glands compared to that of other vertebrates. However, cells of avian body epidermis show a unique lipogenic potential, producing both keratin and sebum like lipoid material. Aptly termed as 'sebokeratocytes', the epidermal cells in glabrous portions of skin as well as specialized regions such as the rictus and toe web exhibit a remarkably high degree of sebogenic activity. Possible significance of this epidermal lipoid secretion in enhancing water repellancy of skin; preventing excessive cutaneous water loss; screening off harmful radiations, imparting colouration to the skin etcetera are discussed. In light of the widespread nature of epidermal lipoid secretion and the knowledge that many specialized types of feathers in various species produce and maintain a supply of material such as powder, grease or both, used in cosmetic purposes, the concept of secretory activity is reexamined. It is proposed that on a functional basis, the secretory epidermal regions and specialized feathers be considered as glandular units of skin, though they lack the conventionally accepted glandular profile.

Ultrastructure comparee des glandes tegumentaires des cochenilles diaspines (Homoptera : Diaspididae)

This study describes the fine structure, function and secretion of the integumentary glands of armored scale insects (Homoptera : Diaspididae). There are 2 types of glandular organizations: (1) glands with ducts, involved in the production of the protective scales; (2) glands without ducts (e.g. peristigmatic glands, protecting the orifices of the spiracles or perivulva glands, protecting the eggs and the vulva area). The glands with ducts are composed of 5 – 6 cells. The central glandular cell has a well-developed rough endoplasmic reticulum, which secretes a glyco-proteinaceous substance; the 2 lateral glandular cells have a well-developed smooth endoplasmic reticulum (SER), which secretes the waxy component of the secretion. The secretion, a white ribbon made up of 2, rarely 3, hollow strands stuck together, the structure of the duct, and especially that of the spinneret responsible for the shape and structure of the secretion, are characteristic of the family Diaspididae. The glandular cells of the peristigmatic and perivulva glands are of only 1 type and have a well-developed SER. The secretion, comprised of long filaments, passes from inside to the outside through a special cuticular structure, having respectively 3 components: filaments, tubular structure and epicuticular pores. The evolution of the wax gland system within the family Diaspididae shows a numerical reduction and concentration. The numerically more reduced, localised and uniform glandular system is found among the Aspidiotini, which are considered as more evolved.

Fine structure of the integumental glands of a termite soldier

The ultrastructure of some integumental glands occurring in the head, thorax and abdomen of K. flavicollis soldiers is described. The secretory units consist of two cells, the canal cell and the secretory cell (this latter filled with secretion granules). A cylindrical and distorted extracellular space, or reservoir, with an irregular outline is lined by short microvilli. The end-apparatus is made up of small overlapping cuticular laminae which in section resemble small wavy rods. The ample distribution of the units has led the authors to consider them dermal glands. Scanning electron micrographs confirm that the glands' activity consists in the secretion of material which then spreads over the surface of the integument. The dissimilar appearance of the secretion granules present in glands of different soldiers suggests that the electron-lucid granules and the granules with fibrils are two completely different secretions at different ages of the animal. The authors do not therefore rule out the hypothesis that these integumental glands may later produce or release pheromones.

Effect of castration and oral administration of sex hormones on some specialised integumentary glands of the male musk shrew,Suncus murinus viridescens (Blyth)

Effect of castration and oral administration of sex hormones on the specialised apocrine sudoriferous glands of the perineal region and the holocrine sebaceous glands of the flank and oral lip regions of the male musk shrew,Suncus murinus viridescens is investigated. Gonadectomy effected a significant regression and hypotrophy of the sudoriferous as well as sebaceous glandular structures of the shrew. The secretory epithelial cells were depleted and the tubules were devoid of any secretory material at the end of one month of castration. Subsequent administration of methyltestosterone daily for four weeks reactivated all these glands, whereas the gross morphological features of sebaceous glands did not vary at any significant level after treatment with ethinyloestradiol daily for four weeks. However, partial rejuvenation in the cellular structures was noticed in all these glands of shrews orally administered with this heterosexual hormone.

An integumentary gland secreting a territorial marking pheromone in Atta sp.: Detailed structure and histochemistry

An abdominal pheromone-producing gland in Atta sp. was examined using light and electron microscopy techniques. The gland is composed of a bunch of juxtaposed secretory units in which the secretory ductules open on to a cribellum close to the sting base. The structure and cycles of the secreting units are described. Each includes a secretory cell with an ‘end apparatus’, ductule cells and epidermal cells. The secretory cycle of glycoproteins accumulated in the ‘end apparatus’ is discussed and a functional interpretation of the morphological components of the application system is proposed.

Integumentary glands ofColumbian ground squirrels (Spermophilus columbianus): Sciuridae.

The integumentary glands of Columbian ground squirrels (Spermophilus columbianus) were examined histologically. In addition to sebaceous glands associated with hair follicles, gland complexes were found in the oral angle, dorsal, and anal regions. The oral angle gland, located immediately posterior to the oral angle, was an apocrine-type gland consisting of three lobes each drained by a separate duct. Approximately 60 individual, oval-shaped glands, extending posterior from the scapular region, made up the dorsal gland field. These glands exhibited an apocrine secretory process and were drained by single ducts. The anal glands were located in retractable papillae near the anal aperture, one median ventral and two lateral. Equal portions of sebaceous and apocrine elements made up the anal glands. Sweat glands were found on the volar surface of the foot pads. Gland structure and location are discussed in relation to behavior patterns that appear to involve secretions from these glands. Possible functions of scent from these integumentary glands are considered briefly.

Ultrastructure des glandes tegumentaires dorsales, secretrices de la “laque” chez la femelle de Coccus Hesperidum L. (Homoptera: Coccidae)

The integumentary glands which secrete the “lac” in the female Coccus hesperidum are located in the dorsal cuticle. Each gland is formed of 4 cells; one central cell, one intermediate cell and 2 identical lateral cells. Two enveloping cells surround the gland. The secretion, called “lac resin” reaches the exterior by way of the canalicule. The secretory product of the lateral cells comes out through a highly differentiated porous region of cuticle at the extremity of the canalicule. It solidifies around the cuticular secretory pore forming a flakey mass. Their function appears to be to reinforce the integument which protects the eggs and larvae gathered under the female.

Histochemistry of Odoriferous Secretions from Integumentary Glands in Three Species of Bats

Secretions from the gular gland of male molossid bats (Tadarida brasiliensis and Molossus bondae) and pararhinal glands of male big brown bats (Eptesicus fuscus) were analyzed histochemically. Proteins and phospholipids were apparently absent from secretions of the glands of all three species. Sebaceous portions of the gular gland of both molossids contained unsaturated neutral lipids; older secretion in distal portions of their ducts consisted of unsaturated neutral and acidic lipids. Cholesterol and its esters and carbohydrates were not detected in sebaceous cells of gular glands. Apocrine secretions from Molossus contained neutral lipids and carbohydrates. Pararhinal glands from Eptesicus consisted of sebaceous and apocrine portions. The former contained neutral lipids and cholesterol esters throughout. Fatty acids were present in apical cells; unsaturated lipids were more prevalent in apical than in basal cells. Apocrine portions of pararhinal glands contained saturated fatty acids, but tests for carbohydrates, proteins, and phospholipids and cholesterol compounds were negative. Histochemical results indicate that at least some of the ester molecules from sebaceous glands are hydrolyzed before release from the gland. Unsaturated, probably short-chain, fatty acids thus released are the most likely components responsible for the well-known odor of these secretions.

A comparative study of scent-gland location and related behaviour in some northwestern nearctic ground squirrel species (Sciuridae): an evolutionary approach

Location and hisiology of integumentary glands were investigated in six species of ground squirrels of the genus Spermophilus found in northwestern North America; S. columbianus, S. undulatus, S. richardsonii, S. tridecemlineatus, S. lateralis, and S. franklinii. Among these species, glands in oral, dorsal, and anal regions were structurally similar. Locations of oral and anal glands were identical but location of individual glands in dorsal-gland fields varied considerably. Gland development was greater in S. columbianus and S. undulatus and least in S. franklinii. Active scent marking was most frequent and extensive in S. columbianus and S. undulatus, less frequent in S. lateralis and S. tridecemlineatus, and absent in S. franklinii. In most instances, greeting behavior (which is focused on the mouth-corner oral-gland area) and the degree of sociality paralleled levels of scent marking. A hypothetical scheme of development or scent marking in relation to habitat and social organization is presented. This scheme fits, in general, classical interpretations of phylogeny.

Ultrastructure des glandes genales dorsales de Campodea sensillifera (Conde et Mathieu) (Diplura)

The dorsal genal glands of Campodea sensillifera are integumentary glands that secrete into the gnathal cavity. They are composed of a great deal of secretory units, each of which consists of 2 proximal glandular cells bearing microvilli at its top, and packed with secretory granules involving microtubular formations, one intermediary cell without secretory characters, and 2 canal cells around the epicuticular canal. Each of these secretory units produces secretion in the common cavity in which the microtubular formations can be observed.

Fine structure of postgonopodial glands of a myriapod Glomeris marginata (Villers)

The postgonopodial gland of the myriapod Glomeris marginata (Villers), which produces a pheromone, is an integumentary gland comprising numerous functional secretory units. Each secretory unit consists of two proximal secretory cells, an intermediary cell lacking secretory characteristics and a canal cell surrounding the canal, which is secretory in nature. Secretory proximal cells exhibit a zone of small channels originating from invaginations of the plasma membrane and through which secreted material is released. Apposing each invagination of these cells is a corresponding invagination of the intermediary cell: the two units in the centre of the intermediary cell join another which communicates with the canal. Secretion produced by the latter passes through the canal wall and blends with secretion of the two proximal cells. The most striking feature of all these cells is the abundance of tubules and fibrils in the small canal zone in the proximal cells, which also exhibits a centriole; in the intermediary cell around cytoplasmic membrane invaginations where a diplosome is present, and in almost the entire canal cell.

Chelonian mental glands.

A survey of 69 of the 74 currently recognized chelonian genera revealed that 21 genera in three families (Emydidae, Platysternidae and Testudinidae) possess paired integumentary glands or gland vestiges in the anterior throat skin. These glands are here termed mental glands; they are holocrine and may be classified morphologically as follows: Class I mental glands are large, complex, multilobed, have specialized ducts, and are found only in the genus Gopherus: Class II mental glands are small, simple sacklike invaginations containing secretory cells or keratinizing cells. The structure of Class II glands varies from distinctive and saccular to shallow keratinized invaginations having no glandular tissue; they are found only in the families Platysternidae and Emydidae. Mental glands occur in 17 of the 22 genera in the subfamily Batagurinae (sensu McDowell, 64); only 2 of 9 genera in the subfamily Emydinae have these glands. The taxonomic occurrence of mental glands suggests that they are primitive structures. The loss of mental glands in most emydines is interpreted as a subfamilial trend toward integumentary simplification.

Ultrastructure des glandes genales ventrales de Campodea Sensillifera Conde et Mathieu et de C. Kervillei Denis (Diplura)

The ventral genal glands of Campodea sensillifera and C. kervillei are integumentary glands that secrete into the gnathal cavity. They are composed of cells which open into a common cavity by means of ductules. The glandular cells have a reservoir without receptor tubules. The cytoplasm is packed with rough endoplasmic reticulum from which secretion granules arise. Secretion is discharged without changes in the ultrastructure of the granules, and is probably proteinaceous in nature. The glands are innervated with axon endings that are without glial sheath and filled with aminergic granules.

‘Milk’ secretion for embryogenesis in a viviparous cockroach

The brood sac of viviparous Diploptera punctata is a typical insect integumentary gland which secretes a ‘milk’ containing protein and carbohydrate to nourish the developing embryos. During gestation the secretory cells proliferate organelles of protein synthesis and secretion and brood sac wet weight, protein content, synthetic activity and secretory output increase five- to six-fold ; a maximum of 0.4 mg protein was collected in 24 hr from one brood sac in a later stage of gestation. Following parturition, when secretory activity ceases, these parameters fall markedly, and the secretory cells decrease their mass by autophagic regression. Acid phosphatase has been located histochemically in autolysomes and assayed in brood sac homogenates; activity reaches a maximum five days after parturition.