Developmental changes in glycosaminoglycans,collagen and collagenase activity in embryonic chick skin

In order to study remodelling of connective tissue during development, changes in glycosaminoglycans, collagen and collagenase activity in embryonic chick skin at various stages have been studied.Collagen content in the skin increased rapidly during days 14 to 18, then leveled off until hatching. Prior to the increase of collagen deposition in the skin, a sharp decrease in chondroitin sulfate was observed between days 11 and 14, while dermatan sulfate increased almost 4 fold during days 12 to 14, then increased steadily until hatching. Hyaluronic acid decreased progressively during the stages investigated (days 11 to 20).At the same stage as the rate of collagen deposition in the tissue became maximal (day 16), the amount of dialyzable hydroxyproline showed a maximum indicating that an increased rate of collagen deposition in the tissue was accompanied by accelerated collagenolysis.Culture of skin from various stages of embryonic development revealed that 16 day old tissue was potentially capable of secreting the highest levels of collagenase. This collagenase was mostly inactive against soluble collagen and collagen fibrils but could be activated by 3 M NaSCN treatment.     

Developmental changes in glycosaminoglycans, collagen and collagenase activity in embryonic chick skin.

In order to study remodeling of connective tissue during development, changes in glycosaminoglycan, collagen and collagenase activity in embryonic chick skin at various stages have been studied. Collagen content in the skin increased rapidly during days 14 to 18, then leveled off until hatching. Prior to the increase of collagen deposition in the skin, a sharp decrease in chondroitin sulfate was observed between days 11 and 14, while dermatan sulfate increased almost 4 fold during days 12 to 14, then increased steadily until hatching. Hyaluronic acid decreased progressively during the stages investigated (days 11 to 20). At the same stage as the rate of collagen deposition in the tissue became maximal (day 16), the amount of dialyzable hydroxyproline showed a maximum, indicating that an increased rate of collagen deposition in the tissue was accompanied by accelerated collagenolysis. Culture of skin from various stages of embryonic development revealed that 16 day old tissue was potentially capable of secreting the highest levels of collagenase. This collagenase was mostly inactive against soluble collagen and collagen fibrils but could be activated by 3 M NaSCN treatment.     

Evolution des activités enzymatiques dans le tractus digestif au cours de la vie larvaire de la sole. Variations des protéinogrammes et des zymogrammes

The activities of digestive enzymes were studied during the course of larval development (from hatching to 30 days) in the sole, Solea solea. No glycosidase activity was present, but alkaline proteolytic activity increased from hatching to day 5, then decreased until day 15. In the acid range, proteolytic activity was relatively stable from the 10th to the 30th day. There were also changes in the number of esterase-like isozymes which increased between day 20 and 30, with minimum activity observed during metamorphosis.     

Choline acetyl transferase activity in chick embryo neuroretinas during development in ovo and in monolayer cultures

The specific activity of the enzyme choline acetyl transferase (CAT) in chick neuroretinas was investigated during in ovo development and in monolayer cultures. The enzyme activity was barely detectable on the 6th day of incubation but increased markedly between the 7th and 11th days. The activity increased sharply between the 15th and 17th days and then slowly until hatching. When cell suspensions from 6- to 7-day neuroretinas were cultured as monolayers, CAT specific activity increased rapidly. After 4–5 days in culture, the activity of the enzyme was identical to that found in the neuroretina on the 11th day of incubation. Cells from 9-day neuroretinas also differentiate in monolayer cultures, but with a more irregular pattern. These data show that cholinergic neurons from chick embryo neuroretina differentiate in monolayer cultures without a lag and at the same rate as in vivo.     

Der Tryptophanstoffwechsel und die Ommochromsynthese während der Embryonalentwicklung der Stabheuschrecke Carausius morosus

The synthesis of ommochromes, ommin, and xanthommatin, was studied during the embryonic development of Carausius morosus. Ommochrome synthesis begins in the epidermis of the embryo at the 46th day after egg laying. The ommochrome accumulation is directly related to the continuous increase of pigment spots on the epidermis of the pharate larva.The concentration of free tryptophan increases progressively from the germ band formation (15th day), until the final position of the embryo in the egg, with the head immediately beneath the operculum (44th day). Subsequent decrease in concentration of tryptophan coincides with the appearance of ommochrome in the epidermis of the embryo. The tryptophan levels decrease considerably from 44th day till the 60th day. During the stage of the pharate first instar larva tryptophan levels remain low until hatching. The concentrations of the intermediates, kynurenine and 3-HO-kynurenine, show no accumulation and remain low during the whole of ommochrome synthesis.     

Histochemical studies on the mucopolysaccharides of the developing chick kidney. II. Mucopolysaccharides of the collecting tubules and excretory ducts.

Mucopolysaccharides of the collecting tubules and excretory ducts of developing chick kidney were studied histochemically to elucidate the relations, between the changing chemical properties of these compounds and excretory processes during pronephric, mesonephric and metanephric developmental stages. At the pronephric ammonotelic stage the collecting tubules contain only neutral mucopolysaccharides, whereas at the mesonephric ureotelic stage neutral mucopoly saccharides are found till the 9th day. Sialic acids make their appearance in luminal border regions of the mesonephric collecting tubules from the 9th day on, their concentration being highest on the 15th day. Hyaluronic acid is observed from the 16th day on. Its concentration is predominant in hatched young birds and increases with age. The physiological significance of alterations in the mucopolysaccharides contents is discussed.     

Acid soluble, short chain esterified and free carnitine in the liver, heart, muscle and brain of pre and post hatched chicks

1. The behaviour of total acid soluble, short chain esterified and free carnitine in the liver, heart, muscle and brain of chick embryos between 11th and 21st day of development and of 8 and 180-day-old chicks is described. 2. Total acid soluble carnitine fluctuates around the same levels in the brain, liver and muscle until 18th day of development, whereas it attains a peak on that day in the heart. At hatching compared to 18th day, it suddenly increases three times in the muscle, drops not significantly in the heart and brain, but sharply in the liver (-40%). However the levels are always higher than those of the grown chick in the brain but lower in the other tissues. 3. Free carnitine levels are almost constant in all tissues during the embryonic life; if compared to adult ones, they are very much lower in the liver, heart and muscle, but higher in the brain, even in 8 day-old chick. 4. Short chain esterified, carnitine reaches a maximum on 18th day of egg incubation in the liver, brain and heart; in the muscle it stays on constant levels until this day and then rapidly increases so that at hatching it doubles the values. 5. The short chain esterified to free carnitine percentage ratio peaks in all tissues on 18th day of development, attaining figures which are well above those determined in the grown chick.     

Post-hatching dynamics of plasma biochemistry in free-living European starlings (Sturnus vulgaris)

This is the first study of plasma biochemical parameters in free-living altricial birds during an entire developmental period in a nest, represented by European starling (Sturnus vulgaris). Dynamics of postnatal changes from hatching until close to fledging (days 1 to 15) were registered. Parameters of protein metabolism represented by total proteins, albumin and globulin concentrations increased continuously during the observed developmental period. There were two peaks in uric acid concentration on days 5 and 11. To the contrary, the creatinine content did not change throughout the observed period and increased only on day 15. Creatine kinase activity gradually increased until day 11 and then fell before fledging. Parameters of lipid metabolism (concentration of total lipids, triacylglycerols and nonesterified fatty acids) in plasma increased gradually reaching a plateau between days 8 and 11 and then declined on day 15. The cholesterol concentration pattern was similar to maximum value on day 11, then consecutively decreased. Concentration of glucose increased until day 8 and remained unchanged until fledging. Whereas calcium reached the highest concentration during days 8 and 11, phosphorus peaked earlier on day 5. The activity of alkaline phosphatase was similar to the pattern found in calcium concentration. Presented data showed an increase in both protein and lipid metabolism during the phase of rapid growth. A remarkable decrease in parameters of lipid metabolism before fledging may reflect increased physical activity and changes in nutrition.     

Change of glycosaminoglycan in pus of patients with purulent pleurisy

The glycosaminoglycan content in pus from patients with purulent pleurisy was studied. The uronic acid content rose in the first 4 hospital days, continued at a high level during hospital days 5-8, and then fell to a low level after 9 hospital days. Four glycosaminoglycans were isolated from the preparation; they were identified as hyaluronic acid, chondroitin 4-sulfate, chondroitin 6-sulfate, and dermatan sulfate. Hyaluronic acid was the main component and its relative proportion increased with increasing hospital days. The relative proportions of chondroitin 4-sulfate and chondroitin 6-sulfate were low during the first 4 day and during Days 10-21, whereas they were high during Days 5-9. The proportion of dermatan sulfate was high during the early hospital days, and thereafter decreased with increasing hospital days.     

First events in lipid absorption during post-embryonic development of the anterior intestine in gilt-head sea bream

Structural development and lipid absorption in anterior intestine of gilt-head sea bream Sparus aurata , were studied by light and electron microscopy during three stages of post-embryonic development: (1) the endotrophic period from hatching day (day 0) to mouth opening day (day 3); (2) the endo-exotrophic period from days 3 to 15; (3) the exotrophic period after day 15. During the 2 days following hatching, there was no trace of lipids in intestinal epithelia. Before mouth opening day, the first lipoproteic particles of endogenous origin appeared in enterocyte endoplasmic reticulum and Golgi apparatus. During the endo-exotrophic period, lipoproteinogenesis increased weakly until day 9, and more greatly between days 9 and 15. It intensified at the beginning of the exotrophic period to remain at a high level afterwards. Until day 15, few transfers of lipoproteins to interenterocyte spaces occurred, whereas no lipoproteins were detectable in the blood flow from days 7 to 9. Their concentration increased slightly between days 9 and 15 to become intense afterwards. Lipid droplets appeared from day 7, and subsisted until the end of endo-exotrophic period. Possible relationships between very low density lipoproteins and chylomicron type lipoproteins and lipid droplets related to lipid excess in food are discussed.     

Change of actin isomers during differentiation of smooth muscle

Changes of actin isomers during development and differentiation of chicken gizzard were investigated by polyacrylamide gel electrophoresis. The two-dimensional gel electrophoresis with SDS-polyacrylamide gels in the presence of urea as the second dimension clearly separated three actin isomers which appear during development of the smooth muscle. The three actin isomers change the relative concentrations during development as follows: gizzard-type gamma-actin begins to be synthesized late on the 7th day of embryogenesis and increases in amount until hatching, nonmuscle-type gamma-actin exists only at earlier stages (before 15 days of embryogenesis), and the amount of beta-actin increases in proportion to the decrease of nonmuscle type gamma-actin, the amount of nonmuscle actin in gizzards then becoming constant. Actin composition of gizzard before 7 days of embryonic age was nonmuscle type and consisted of beta-actin and nonmuscle-type gamma-actin. These observations indicate that developmental process of gizzard smooth muscle cells are classified as three stages: nonmuscle, intermediate and smooth muscle stages.     

Phospholipid biosynthesis in sarcoplasmic reticulum membrane during development.

Biosynthesis of phosphatidic acid, phosphatidylcholine and phosphatidylethanolamine in the sarcoplasmic reticulum membrane has been investigated. The results show that sarcoplasmic reticulum, in addition to its main function, i.e. transport and accumulation of Ca2+, is able to synthetize phospholipids by the same pathways as endoplasmic reticulum of other tissues. The changes of activity of enzymes involved in phospholipid biosynthesis during muscle development have been analysed. The extent of sn-glycero-3-phosphate and lysophosphatidylcholine acylation by acyl-CoA or free fatty acids in the presence of ATP and CoA is the same at every stage of development. The specific activity of glycerolphosphate acyltransferase(s) increases progressively during development up to about the 10th day of postnatal life and then decreases to the adult level. Linoleate esterifies sn-glycero-3-phosphate to a higher extent than palmitate, especially during postnatal period. The main product of sn-glycero-3-phosphate acylation is phosphatidic acid. The specific activity of lysolecithin acyltransferase increases from the embryonic period to a maximum between the 4th and the 9th day of postnatal life followed by a decrease to the adult value. the low embryonic value to a maximum at about the 3rd day of postnatal life, followed by a decrease to the adult value. The activity of cholinephosphotransferase decreases from a high value observed during the earliest embryonic period studied until the 3rd day before birth, and then begins to increase again from about the 5th day of postnatal life. The activity of ethanolaminephosphotransferase decreases continuously with age. The main product of phosphatidylethanolamine methylation is phosphatidylmonomethylethanolamine. The specific activity of phosphatidylethanolamine methyltransferase increases from     

Changes in the adrenal steroidogenic responsiveness of the mallard duck (Anas platyrhynchos) during early post-natal development

1. Plasma concentrations of corticosterone (B), aldosterone (Aldo) and deoxycorticosterone (DOC) were measured in mallard ducklings immediately before and after exposure to acute immobilization stress. 2. Except for transient declines in B and DOC between the 4th and 14th days after hatching, the resting concentration of each hormone did not change significantly during post-natal development. 3. The stress-induced in Aldo was maximal at hatching while maximal increases in B and DOC did not occur until one day later. 4. Thereafter the magnitude of the stress-induced increases in the concentrations of all of the hormones decreased steadily and on the 21st and 28th days after hatching only B increased significantly in response to stress.     

Behavior and Movement of Wild Turkey Broods

Behavioral and movement ecology of broods are among the most poorly understood aspects of wild turkey (Meleagris gallopavo) reproductive ecology. Recent declines in wild turkey productivity throughout the southeastern United States necessitate comprehensive evaluations of brood ecology across multiple spatial scales. We captured and marked 408 female wild turkeys with global positioning system (GPS)-transmitters across 9 pine (Pinus spp.)-dominated study sites in the southeastern United States during 2014–2019. We evaluated various aspects of the behavioral and movement ecology of 94 brood-rearing females until brood failure or 28 days after hatch (i.e., when poults are classified as juveniles). We found that 34 (36.2%) females had broods (≥1 poult) survive to 28 days after hatch. Broods moved >500 m away from nest sites the day after hatching, and then moved progressively farther away from nest sites over time. Daily movements increased markedly the first 3 days after hatching, and broods moved >1,000 m/day on average thereafter. Females roosted broods an average of 202 m away from nest sites the first night after hatching, but distances between consecutive ground or tree roosts were variable thereafter. Daily core areas increased from 0.8 ha the day of hatch to 4.6 ha by day 28, and range sizes increased from 6.9 ha to 27.9 ha by day 28. Broods tended to consistently select open land cover types, whereas selection for other land cover types varied temporally after hatch day. Broods spent 89% of their time foraging. Predicted daily survival for broods decreased rapidly with increasing distance moved during the initial 3 days after hatching and showed less variation during the subsequent 2 weeks post-hatch. Our findings parallel previous researchers noting that the most critical period for brood survival is the first week after hatch day. Previous researchers have attempted to identify vegetative communities used by broods under the assumption that these communities are a primary factor influencing brood success; however, our results suggest that brood survival is influenced by behavioral decisions related to movements during early brooding periods. © 2020 The Wildlife Society.     

Plasma iodothyronines in the domestic fowl: newly hatched to early adult stages, with special reference to reverse triiodothyronine (rT3)

Circulating concentrations of thyroxine (T4), triiodothyronine (T3) and reverse triiodothyronine (rT3) were measured in chicks before, during, and after hatching, up to 9 weeks of age. T4 decreased prior to hatching, rose after emergence, and was variable in the immature domestic fowl. T3 increased prior to emergence, decreased until 5 days after hatching, and increased again by 1 week of age, after which the levels declined. Plasma rT3 declined prior to hatching, remained low until 5 days after emergence, and then increased, again, to 0.14-0.19 ng/ml between 1-9 weeks of age.     

Variation of DNA polymerase activities in chick neural retina as a function of age

The activities of DNA polymerases alpha, beta, and gamma and of thymidine kinase were determined in the chick neural retina at different stages of embryonic development (starting at seven days) and after hatching (up to five years). Crude extracts of neural retinae were fractionated by centrifugation on sucrose gradients and the enzymatic activities measured using specific assays. The DNA polymerase alpha activity decreases greatly between 7 and 11 days of incubation. This decrease parallels the decline in mitotic activity. However, a constant residual activity remains after hatching, even in the oldest animals. DNA polymerase beta activity increases slightly between 7 and 14 days of incubation; it then decreases slowly until seven days after hatching and remains constant thereafter. DNA polymerase gamma activity is maximal between 7 and 14 days of incubation and then decreases until hatching. The activity of thymidine kinase increases slightly during the embryonic life until hatching and remains almost constant thereafter. The implication of these enzymes in DNA replication and repair processes is discussed.     

Variation of DNA Polymerase Activities in Chick Neural Retina as a Function of Age

The activities of DNA polymerases α, β, and γ and of thymidine kinase were determined in the chick neural retina at different stages of embryonic development (starting at seven days) and after hatching (up to five years). Crude extracts of neural retinae were fractionated by centrifugation on sucrose gradients and the enzymatic activities measured using specific assays. The DNA polymerase a activity decreases greatly between 7 and 11 days of incubation. This decrease parallels the decline in mitotic activity. However, a constant residual activity remains after hatching, even in the oldest animals. DNA polymerase β activity increases slightly between 7 and 14 days of incubation; it then decreases slowly until seven days after hatching and remains constant thereafter. DNA polymerase γ activity is maximal between 7 and 14 days of incubation and then decreases until hatching. The activity of thymidine kinase increases slightly during the embryonic life until hatching and remains almost constant thereafter. The implication of these enzymes in DNA replication and repair processes is discussed.     

Pre-natal development of the adrenal gland in the mallard duck (Anas platyrhynchos)

Summary The differentiating nephrotome in the 10-day-old mallard duck embryo is able to synthesize corticosterone, aldosterone and deoxycorticosterone even though an adrenal anlage cannot be identified histologically until the 12th day of incubation. At this time, sudanophilic cells containing much smooth endoplasmic reticulum and numerous mitochondria with tubular cristae are located adjacent to the developing mesonephros. Chromaffm cells appear in this region on about the 14th day of embryogenesis. A discrete glandular structure containing measurable quantities of corticosteroids can be identified on the 15th day, and during the next 2 days the tissue becomes encapsulated. Concomitantly, the ACTH-inducible rates of corticosteroid hormone synthesis increase several fold. The corticotropic responsiveness of the developing adrenal steroidogenic tissue increases progressively during the remainder of embryogenesis.This work was supported by grants to James Cronshaw and W.N. Holmes from the University of California Committee on Research and the National Science Foundation (DIR-8820923), Washington, DC, USA     

Change of actin isomers during differentiation of smooth muscle

Changes of actin isomers during development and differentiation of chicken gizzard were investigated by polyacrylamide gel electrophoresis. The two-dimensional gel electrophoresis with SDS-polyacrylamide gels in the presence of urea as the second dimension clearly separated three actin isomers which appear during development of the smooth muscle. The three actin isomers change the relative concentrations during development as follows: (1) gizzard-type γ-actin begins to be synthesized late on the 7th day of embryogenesis and increases in amount until hatching, (2) nonmuscle-type γ-actin exists only at earlier stages (before 15 days of embryogenesis), and (3) the amount of β-actin increases in proportion to the decrease of nonmuscle type γ-actin, the amount of nonmuscle actin in gizzards then becoming constant. Actin composition of gizzard before 7 days of embryonic age was nonmuscle type and consisted of β-actin and nonmuscle-type γ-actin. These observations indicate that developmental process of gizzard smooth muscle cells are classified as three stages: nonmuscle, intermediate and smooth muscle stages.     

Digestive enzyme activities in larvae of sharpsnout seabream (Diplodus puntazzo)

The ontogenesis and specific activities of pancreatic and intestinal enzymes were investigated in sharpsnout sea bream, Diplodus puntazzo, during larval development until the end of weaning on day 50. The green-water technique was carried out for larval rearing in triplicate. Trypsin was first detected as early as hatching and sharply increased related to age and exogenous feeding until day 25, but a sharp decrease was observed towards the end of the experiment. Amylase was determined 2 days after hatching (DAH) and sharply increased to 10 DAH. Afterwards, slight decreases were found between 10 and 20 DAH and then slow alterations were continued until end of the experiment. Lipase was measured for the first time on day 4, and then slight increase was found to 25 DAH. After this date, slow variations were maintained until end of the experiment. Pepsin was firstly assayed 32 DAH related with stomach formation and sharply increased to 40 DAH. Then it was fluctuated until end of the experiment. Enzymes of brush border membranes, alkaline phosphatase and aminopeptidase N, showed similar pattern on specific activities during the first 10 days. Thereafter, while specific activity of alkaline phosphatase slightly decreased to 15 DAH and fluctuated until 20 DAH, aminopeptidase N activity slowly declined to 20 DAH. Afterwards, activity of alkaline phosphatase and aminopeptidase N were sharply increased to 30 DAH, showing maturation of the intestinal digestive process and also these activities continued to slight increase until end of the experiment. The specific activity of cytosolic peptidase, leucine-alanine peptidase sharply increased to on day 8, then suddenly declined to 12 DAH and further decreased until 20 DAH. After this date, in contrast to enzymes of brush border membranes, it sharply decreased to 25 DAH and continued to gradually decline until the end of the experiment. These converse expressions were indicative of a maturation of enterocytes and the transition to an adult mode of digestion.