Tavuk (Gallus domesticus) ve bıldırcın (Coturnij coturnij Japonica) derisi üzerinde morfolojik araştırmalar

Abstract

. ÖZET Bu çalışma, kanatlı hastalıkları üzerinde yapılacak araştırmalara yararlı olması amacıyla yapıldı. Araştırmada, prenatal dönemdeki gelişmeleri incelemek üzere yüzer (100) adet döllü tavuk ve bıldırcın yumurtası, postnatal dönem için ise, el l işer (50) adet tavuk ve bıldırcın kullanıldı. Döllü tavuk ve bıldırcın yumurtala rı ndan, ışık mik roskopik incelemeler için 5. günden, elektronmikroskopik in celemeler için ise, 7. günden itibaren yumurtadan çıkışa ka dar ikişer gün arayla materyal alındı. Postnatal dönem için yumurtadan çıkışın 1. gününden başlayarak, bir haftalık, on- beş günlük ve altı aylık (ergin) tavuk ve bıldırcından deri örnekleri alındı. Bu örnekler, altı aylık döneme kadar sırt bölgesinden, altı aylık tavuk ve bıldırcından ise sırt, ka rın ve but bölgelerinden sağlandı. İncelenen ışık-ve elektronmikroskopik preparatl arda, 5, 7 ve 9 günlük tavuk ve bıldırcın embriyoları derisinin pe riderm ve epiderm olmak üzere iki katmandan meydana geldiği gözlendi. 11 ve 13 günlük tavuk embriyo derisi, önceki dönem- Tene benzer özellikler göstermesine karşın 11 günlük bıldırcın embriyosunun periderm ve epiderm katmanları, ikişer hücre arasından meydana gelmekteydi. 13 ve 15 günlük bıldırcın embri yosunda, periderm in üst katmanındaki hücrelerin ileri derece de yassı l aştı ğı, derin katmandaki hücrelerin ş işkinl eştiği,44 sitopl azmal arı nda organellerin kaybolarak yerini fibröz bir materyalin doldurduğu gözlendi. 15 günlük tavuk embriyosunda periderm'in iki, epiderm'in üç hücre katmanından meydana gel diği ve periderm'in, epiderm'e komşu olan hücrelerinde, peri derm granülleri içerdiği görüldü. 17 günlük tavuk embriyosun da periderm iki sıralı halini korurken, epiderm 4-5 sıralı hücre dizisinden oluşmaktaydı. Bu dönemde periderm granüllerinin sa yı ve büyüklüğünde artış gözlendi. 17 günlük bıldırcın embri yosunda ise periderm kaybolmuş, epiderm ise, ergin epidermis yapısını kazanmıştı. 19 günlük tavuk embriyosunda

46 7. SU M MARY MORPHOLOGICAL STUDIES ON THE SKIN OF CHICKEN (GaTlus domesticus) AND QUAIL (Coturnix coturnix Japonica) This study was performed for the purpose of being of value to research work to be done on poultry diseases. Embryonated chicken eggs(n:100) and quail eggs(n:100) were used for the examination of development in the prenatal per riod; chickens (n:50) and quails (n:50) were used for the postnatal period. Samples for light microscopy were taken from embryo nated chicken and quail eggs every 2 days from day 5 onwards andfor electron microscopy from day 7 onwards until hatching. For the postnatal period, skin samples were collected from hatching to 1-, 2-and 24-week-old chickens and quails. These samples were obtained from the back region until the age of 6 months and from the back, abdomen and thigh region in chickens and quails 6 months old. The embryos of five-, seven-and nine-day-old chickens and quails had skin consisting of two layers called the pe riderm and epiderm which were observed in sections examined by light and electron, microscop.. Although 11 and 13-day-old chicken embryos' skin showed similar features to previous pe riods; 11-day-old quail embryos' skin was two cells thick in both the periderm and epiderm. In the outer layer of the periderm, the cells were highly flattened, the deeper cells47 were swollen and the cytoplasmic organelles had disappeared and were replaced by fibrous material in 13-and 15-day-old quail embryos. The periderm and epiderm in the 15-day-old chicken embryos consisted of two and three layers of cells respectively o The periderm cells adjacent to the epiderm had periderm granules. While the periderm preserved its to layers the epiderm was composed of 4-5 layers of cells in 17-day-old chicken embryos» Increases in the volume and numbers of the periderm granules were observed in this period. The periderm disappeared and the epiderm transformed into a mature epider mis structure in 17-day-old quail embryos. While the periderm cells still had granules, other organelles vanished and the cytoplasm became occupied by fibrous material; the epiderm reached a characteristic mature epidermis in 19-day-old chicken embryos. The epidermis had str.basale, str` intermedium, str. transitivum and str.corneum in newly hatched 1 -,2-and 24- week- old chickens and quails. The epidermis of the back and abdo minal regions was thicker than the thigh region in adult chickens an quails (24-week-old). Two cell types called keratinocytes and Langerhans cells were observed in the epidermis» The number of lipid globules in the keratinocyte increased from the basal to the outer parts and these globules were the source of the lipid material on the skin surface and in the str.corneum. The dermis developed simultaneously with the epidermis in the embryonal stage. Mesenchymal cells, fibroblasts and48 nerve fibers were found in 5- arid 7-day-old chicken and quail embryos. In the later development stages blood vessels, nerve fibers, connective tissue fibers and fibroblasts were encoun tered- in increasing amounts in the dermis. The dermis in newly hatched 1-, 2- and 24-week-old chickens and quails had str` superf iciale, str` compactum, str.laxum and lamina elastica. The subcutis consisting of loose connective tissue was present just under the dermis. Myelinated and unmyelinated nerve fibers were seen as thick bundles in the deeper parts and as small bundles in the outer parts of the dermis» Nerve fibers leaving the small bundles innervated the feather follicles, the smooth muscles -land the Herbst corpuscles. Mastocytes were detected around the nerve fibers in the dermis adjacent to the epi dermis. Herbst corpuscles of various sizes were seen near the feather follicles in the dermis,, More than one Herbst corpuscle per feather follicle were also found. This corpuscle had an outer layer composed of a connective tissue capsule, a subcap- suler space and a central nerve fiber with bilaterally arran ged Schwann cells. The nerve fiber surrounded by numerous flat tened lamellae developed in the Schwann cell cytoplasm.