Tissues Of Japanese Quail Research Articles

Identification of Reference Genes for Quantitative Gene Expression Studies in Three Tissues of Japanese Quail.

RT-qPCR is the gold standard for candidate gene expression analysis. However, the interpretation of RT-qPCR results depends on the proper use of internal controls, i.e., reference genes. Japanese quail is an agronomic species also used as a laboratory model, but little is known about RT-qPCR reference genes for this species. Thus, we investigated 10 putative reference genes (ACTB, GAPDH, PGK1, RPS7, RPS8, RPL19, RPL32, SDHA, TBP and YWHAZ) in three different female and male quail tissues (liver, brain and pectoral muscle). Gene expression stability was evaluated with three different algorithms: geNorm, NormFinder and BestKeeper. For each tissue, a suitable set of reference genes was defined and validated by a differential analysis of gene expression between females and males (CCNH in brain and RPL19 in pectoral muscle). Collectively, our study led to the identification of suitable reference genes in liver, brain and pectoral muscle for Japanese quail, along with recommendations for the identification of reference gene sets for this species.

Bioaccumulation of Lead in the Tissues of Japanese Quails and Its Effects on Blood Biochemical Factors

Background: Lead is the oldest known toxic metal, physiologically and biologically harmful to living creatures. This study aimed to evaluate the lead accumulation in the liver and breast muscles of Japanese quail (Coturnix japonica) and to compare concentrations in both sexes and its effect on blood biochemical factors. Methods: Twenty-four young farm Japanese quails (25 day old) prepared from local breeders in December 2014 and randomly divided into control and treatment group. Treatment group were exposed to 0.4 mg per kg diet of “Lead Acetate” for 21 days. We studied the effects of lead on survival and blood biochemical factors. The lead accumulation in the liver and breast muscles of Japanese quail was determined using atomic absorption. Results: Exposure to lead caused a significant increase in the activity of enzymes (AST), (ALT), (LDH), glucose, creatinine and uric acid in poultry treated with lead compared with the control group (P<0.05). In addition, significant decrease in the activity of ALP, AChE, total protein, albumin, globulin, and triglycerides was found (P<0.05). The treated group had no significant change in the activity of CPK and cholesterol. Lead accumulation was more in the liver rather than the breast muscle. There was no significant difference between males and females as for concentration of lead in muscle and liver of quail. Conclusion: Quail have capabilities to accumulate lead in their tissues. In addition, it can lead to apparent changes in enzymes and blood biochemical factors, which show adverse effects of heavy metals on the immune and physiological system of birds.

Inhibitory Effect of Nigella Sativa Seeds and Curcumin on Hepatotoxicity Induced By Aflatoxin in Japanese Quails Associated With DNA Damage

This study is aimed to investigate the adverse effects of Aflatoxin (AFs) on performances, immunity and some biochemical parameters in serum and tissues of Japanese quails as well as to evaluate the possible protective effects of Nigella sativa (NS) crushed seeds and Curcumin powders to overcome the adverse effects of AFs. A total 120 unsexed Japanese quails chicks were divided equally into 4 groups; control group (G1), AFs group 2.5 ppm (G2), AFs 2.5 ppm plus Nigella sativa 1.5% (G3) and AFs 2.5 ppm plus Curcumin powders 400 mg/ kg diet (G4) for one month of experiment. AFs induced hepatotoxicity and immunosuppressive revealed by significant decrease in B.W, total leukocytes count and lymphocytes percent, while increase in heterophils percent, it also induced a significant decrease in serum total protein, albumin and globulin, on the other hand significant increase in alanine aminotransferase (ALT) and aspartate aminotransferase (AST), significant decrease in superoxide dismutase (SOD) and reduced glutathione (GSH) activity, while significant increase in malonaladahyde activity (MDA) and also in DNA fragmentation. Treatment with NS and Curcumin produce significant increase in B.W, TLC and lymphocytes percent, while decrease in heterophils percent, significant increase in total protein, albumin and globulin, on the other hand significant decrease in ALT and AST, significant increase in SOD, GSH activity and significant decrease in MDA activity and significance decrease in DNA fragmentation. This study indicated that treatment with Nigella sativa and Curcumin improved the adverse effects of AFs on performances, immunity, some biochemical parameters in serum and tissues and also gave more protection for DNA from fragmentation

Novel needle-in-straw vitrification can effectively preserve the follicle morphology, viability, and vascularization of ovarian tissue in Japanese quail (Coturnix japonica)

Cryopreservation of ovarian tissue has been the only effective way of ex situ conservation of female germplasm in avian species. A novel needle-in-straw (NIS) vitrification method was developed to store tissue in straws instead of cryovials. Fragments of ovarian tissue from one-week old Japanese quail were transfixed on an acupuncture needle. They were immersed in equilibration and vitrification solutions containing dimethyl sulphoxide, ethylene glycol and sucrose. A layer of tin foil was rolled over the tissue fragments and the tin foil package was plunged into liquid nitrogen and inserted into a pre-cooled, 0.5-ml straw which was stored in liquid nitrogen. Tissue was also preserved using a needle immersed vitrification (NIV) method, in which tissue fragments transfixed on needles without tin foil and were stored in cryovials filled with liquid nitrogen. Cryopreserved tissue was warmed at room temperature (RT) or 37°C and the ratio of normal follicles to total visible follicles was determined by histological methods. In addition, cryopreserved and warmed tissue was cultured on the chorioallantoic membranes of fertilized chicken eggs for 5–6 days. The viability and vascularization of the grafts were evaluated. The tissue cryopreserved by NIS and warmed at RT showed comparable follicle morphology to fresh tissue and to that preserved by NIV and warmed at RT. No significant impairment on the viability or vascularization of the grafted tissue was observed. The NIS method allows tissue to be stored and transported safely and efficiently and can be used instead of cryovials in tissue cryobanking.

The effects of a novel vitrification device and warming temperature on the histology of ovarian tissue in Japanese quail

The effects of a novel vitrification device and warming temperature on the histology of ovarian tissue in Japanese quail

Production of Donor-Derived Offspring from Cryopreserved Ovarian Tissue in Japanese Quail (Coturnix japonica)1

Cryopreservation of avian ova and embryos is challenging because of the yolky structure of the egg. As an alternative, with the development of effective cryopreservation protocols, ovarian tissue cryopreservation could be used for cryobanking for birds. Pieces of ovarian tissue of week-old Japanese quail (Coturnix japonica) were frozen at 0.5 degrees C/min in a programmable freezer or vitrified by immersion in liquid nitrogen. Straws containing slow-frozen samples were thawed in ice water, and vitrified samples were removed from the vials and transferred into sucrose, with the concentration lowered in sequence at room temperature. Cell viability of tissue was estimated by trypan blue assay, and tissue histology was examined by light microscopy. Frozen-thawed or vitrified-warmed tissue from WB (recessive plumage color) chicks was transplanted into week-old ovariectomized QO (wild-type plumage) chicks, with some chicks receiving fresh tissue as a control group. At sexual maturity, QO recipients were mated to WB males, and the production of WB offspring demonstrated successful cryopreservation and transplantation. Donor-derived offspring were obtained from the ovarian tissue that had been cryopreserved by either slow-freezing or vitrification. The vitrification protocol used in this study showed better outcomes at each level of evaluation. This study demonstrated that the function of ovarian tissue in avian species can be successfully preserved at subzero temperatures and recovered by transplantation. The vitrification protocol is recommended because of high efficiency and overall simplicity.

Comparison of rhodanese distribution in different tissues of Japanese quail, partridge, and pigeon

Rhodanese (thiosulfate: cyanide sulfurtransferase, EC. 2.8.1.1) is a ubiquitous enzyme present in all living organisms, from bacteria to humans, and plays a central role in cyanide detoxification. The purpose of this investigation was to determine and compare the pattern of distribution of rhodanese in different tissues of adult Japanese quail, partridge, and pigeon. In the three species studied, rhodanese was present in all tissues albeit in different amounts. The highest activity of rhodanese in Japanese quail was observed in kidney and proventriculus followed by liver and heart. In partridge, the highest activity of the enzyme was observed in heart, kidney, and proventriculus. In pigeon, the highest activity of the enzyme was observed in liver, kidney, and heart. Inter-species differences were seen in the level of enzyme in different tissues. The results of this study may indicate the involvement of rhodanese in cyanide detoxification in tissues that have greater potential to be exposed to higher levels of cyanide and also involvement of rhodanese in functions other than cyanide detoxification in other tissues.

Residues of fluoroquinolone drugs in the cloacal gland and other tissues of Japanese quail

1. In this study we investigated the residues of fluoroquinolone drugs (ciprofloxacin and pefloxacin) in the cloacal gland (a site of foam synthesis) and other tissues such as breast muscle, testes, brain, kidney and plasma. 2. Fifty-four healthy male Japanese quail were selected at random from a flock, maintained under uniform husbandry conditions and divided into three groups, each of 18 birds. Group I (control) received 1 ml vehicle (normal saline 0·9% (w/v) NaCl) daily for 12 d through the intraperitoneal route. Birds of groups II and III received ciprofloxacin and pefloxacin by the same route at the rate of 10 and 12 mg/kg body weight, respectively, every day for a similar period. 3. Birds from each group were killed, at 1, 5 and 10 d after the cessation of treatment, to collect the cloacal gland together with other tissues that were analysed for residual drugs. 4. Cloacal gland retained the maximum drug residues of ciprofloxacin (60%) and pefloxacin (80%) on d 10 compared with that on d 1 after drug withdrawal. The drug residues were found 60 and 80% in ciprofloxacin and pefloxacin groups, respectively, in the cloacal gland tissue even on d 10 after withdrawal of the treatment. 5. In the ciprofloxacin-treated group, all tissues except cloacal gland contained very small amounts of the drug residues on d 10 after treatment ended. In the pefloxacin group the cloacal gland, breast muscle and kidney retained a fairly high amount of drug even on d 10 after treatment ceased. No residues of pefloxacin were detectable in testes and brain throughout. 6. In conclusion, the cloacal gland in Japanese quail acted as the largest sink for the fluoroquinolone drugs. Ciprofloxacin was more widely distributed in different tissues and persisted for a shorter period than pefloxacin.

Retinoid nutritional status differently affects the expression of Japanese quail retinoic acid receptor-beta isoform transcripts in a tissue-specific manner.

We investigated the effects of vitamin A (VA) nutritional status on the levels of expression of retinoic acid (RA) receptor-beta (RARbeta) gene in the various tissues of Japanese quail. VA deficiency caused a significant decrease in the mRNA levels of brain, liver, heart, lung and kidney RARbeta2/beta4, whereas no change was observed in the level of testis RARbeta2 transcript. In contrast, reduction in the RARbeta1 transcript caused by VA depletion was observed only in the lung, remaining unchanged in the other tissues. The administration of RA to the VA-deficient quail rapidly induced the expression of RARbeta2/beta4 mRNAs in all the tissues examined, but RA increased the expression of RARbeta1 transcript in the liver, heart, lung and kidney at a lower magnitude. RA could not change the expression of the brain RARbeta1 transcript, while it induced the expression of the testis RARbeta1 mRNA in a temporal way. These results clearly indicate that VA nutritional status differently regulates the expression of RARbeta1 and RARbeta2/beta4 transcripts in a tissue-specific manner.

Effects of 6-aminonicotinamide on levels of soluble proteins and enzyme activities in various tissues of Japanese quail

The effects of 6-aminonicotinamide (6-AN) on the levels of soluble proteins and enzyme activities in various tissues of Japanese quail were investigated. SDS-polyacrylamide gel electrophoresis showed that the soluble proteins with molecular masses corresponding to 160.4 and 52.5 kDa were either missing or present at lower concentrations in the brain of the 6-AN treated group compared to those in the control group. The soluble liver proteins with molecular masses 200, 120 and 70.5 kDa were missing in the treated group compared to those in the control while those of a molecular mass 15.1 kDa were found to be present at higher concentrations. Similarly, treatment with 6-AN decreased the concentration of soluble proteins in pectoral muscle with molecular masses 92.3, 54.5, 43.5, 41.2, 34.5, 27.5, 20.1 and 17.5 kDa and increased those with molecular masses 96.5, 37.7, 25.0, 19.3, 16.6, 13.8 and 10.8 kDa. In the heart, soluble proteins with molecular mass 84.6 kDa were increased. There was a marked reduction in the treatment group in the concentration of NAD in pectoral muscle but not in other tissues. A similar observation was also made with total RNA levels. The specific activity of malic enzyme was markedly increased by 6-AN treatment in the kidney and pectoral muscle but reduced in the liver. 6-Phosphogluconate dehydrogenase and lactate dehydrogenase activities were markedly reduced in the liver. Glyceraldehyde-3-phosphate dehydrogenase activity was significantly decreased in liver and pectoral muscle. NAD glycohydrolase activity was markedly decreased in pectoral muscle. Acetylcholinesterase activity was markedly reduced in liver but was enhanced in pectoral muscle. The results suggest that the metabolic actions of 6-AN are specific for certain proteins in the liver and muscle with the effect being most pronounced in muscle. The effects are also quite distinct from those shown by its analogue 3-acetylpyridine.

Effects of niacin deficiency on the levels of soluble proteins and enzyme activities in various tissues of Japanese quail

The effects of niacin deficiency on the levels of soluble proteins and enzyme activities of Japanese quail have been investigated. SDS–polyacrylamide gel electrophoresis revealed that in the pectoral muscle the soluble proteins with molecular masses corresponding to 181, 128, 93, 76, 72, 62, 56, 43, 41, 28 and 20 kDa were present in lower amounts but those of 60, 50 and 37 kDa were present in higher amounts. In the heart the soluble proteins with a molecular mass of 181 kDa were present in lower amounts and in the brain those of 43 kDa were present in lower amounts but those of 221 kDa were present in higher amounts. In the intestine the soluble proteins with molecular masses corresponding to 181, 102, 83, 74, 72, 44 and 40 kDa were present in lower amounts but those of 41 kDa and 18 kDa were present in higher amounts. There was a marked reduction in the level of NAD and NADPH in the pectoral muscle of niacin deficient quail but not in other tissues. The specific activity of glyceraldehyde-3-phosphate dehydrogenase decreased markedly both in the liver and pectoral muscle of niacin deficient quail whereas that of 6-phosphogluconate dehydrogenase and malic enzyme decreased markedly in the liver or pectoral muscle, respectively. In contrast, the specific activity of acetylcholinesterase and carboxypeptidase increased markedly in the liver or the pectoral muscle, respectively. The results suggest that a severe niacin deficiency exerted specific effects on levels of some soluble proteins particularly in the pectoral muscle and intestine and on activities of certain enzymes in the liver and the pectoral muscle.

Effects of the neurotoxin 3-acetylpyridine on levels of soluble proteins and enzyme activities in various tissues of Japanese quail

(1) The effects of the neurotoxin 3-acetylpyridine on the levels of soluble proteins and enzyme activities in various tissues of Japanese quail were investigated. (2) SDS-polyacrylamide gel electrophoresis showed that in the brain the soluble proteins with a molecular mass corresponding to 18 kDa were increased in quail treated with this toxin. The soluble liver proteins with the largest molecular masses (200, 120, 98, 80.5 and 58 kDa) were either missing or present at lower concentrations in the treated group compared to those in the controls while those of lower molecular mass (62, 55, 45, 36.5 and 24 kDa) were found to be present in higher concentrations. Similarly, treatment with 3-acetylpyridine tended to decrease the concentration of soluble proteins in pectoral muscle having a high molecular mass (160, 98, 60, 33, 30.5, 22 and 14 kDa) and to increase those having a low molecular mass (26, 20, 19.5 and 16 kDa). (3) There was a marked reduction in the treatment group in the concentration of NAD in pectoral muscle but not in other tissues. A similar observation was also made with total RNAs levels. (4) The specific activity of malic enzyme and glyceraldehyde-3-phosphate dehydrogenase was markedly reduced in the liver and pectoral muscle of the treatment group but was not affected in other tissues. The specific activity of 6-phosphogluconate dehydrogenase was significantly lower in the liver only, and that of lactic dehydrogenase and acetylcholinesterase was not affected in any of the tissues examined. (5) The results suggest that the metabolic actions of 3-acetylpyridine are quite distinct from those shown by niacin deficiency and its analog such as 6-aminonicotinamide.

Apolipoprotein A-1 of Japanese quail: cDNA sequence and modulation of tissue expression by cholesterol feeding.

Apolipoprotein (apo) A-1 cDNA was amplified by the reverse-transcriptase-polymerase chain reaction (RT-PCR). Primers were synthesized according to the nucleotide sequence of chicken apo A-1, and the identity of apo A-1 cDNA was confirmed by comparing with the N-terminal amino acid sequence. The open reading frame of apo A-1 cDNA consists of 795 nucleotides, and it is capable of coding a polypeptide of 264 amino acids. A comparison between quail and chicken apo A-1 revealed 94.5% homology in the nucleotide sequence and 91.7% homology in the amino acid sequence. There was a similar 11- or 22-amino acid repeat in quail apo A-1 as was the case for chicken apo A-1. Apo A-1 mRNA was evaluated to be 1.4 k in length and was expressed in various tissues of Japanese quail: the liver, small intestine, lung, kidney, heart, and muscle. A quantitative evaluation, however, revealed that the liver and small intestine were the major organs for apo A-1 synthesis, accounting for more than 90% of the total expression of apo A-1 mRNA. Besides apo A-1 mRNA (1.4 k in length), a transcript of 4.1 k was detected in all the tissues examined, with a magnitude ranging from 5 to 10% of the apo A-1 mRNA level. The effect of cholesterol level on the expression of apo A-1 mRNA was studied to address the physiological significance of apo A-1 in the liver, small intestine, and muscle. The level of cholesterol in the liver and breast muscle was increased by feeding with cholesterol and reached a saturation level at day 7. There was also a temporal rise of cholesterol level at day 7 in the small intestine. Dietary cholesterol increased the expression of apo A-1 mRNA two fold in both the liver and small intestine. This was not the case for breast muscle, in which the expression of apo A-1 mRNA was not modulated by the cholesterol level.

Effect of prolonged starvation on the activities of malic enzyme and acetylcholinesterase in tissues of Japanese quail

During starvation muscle protein degradation is increased but the mechanism for this is uncertain. In this study Japanese quail were starved for 5 days and the activities of malic enzyme and acetylcholinesterase were determined in various tissues. SDS-polyacrylamide gel electrophoresis showed that the soluble proteins with molecular weights corresponding to 160, 120, 108, 99 and 38 kDa were absent in the liver of the starved group. In the pectoral muscle the soluble proteins with molecular weights corresponding to 69, 41 and 34 kDa were missing. The activity of malic enzyme in the liver, heart and pectoral muscle of the starved group decreased markedly whereas that of acetylcholinesterase increased markedly in the pectoral muscle (P < 0.005). It is concluded that in prolonged starvation acetylcholinesterase synthesis may be induced in tissues being subjected to protein catabolism and that this enzyme may be involved as a protease in protein degradation.

Distribution of Ascorbic acid in Tissues of Japanese Quail (Coturnix coturnix japonica) Administrated Adrenocorticotropic Hormone

Distribution of Ascorbic acid in Tissues of Japanese Quail (Coturnix coturnix japonica) Administrated Adrenocorticotropic Hormone

Effects of niacin deficiency on the relative turnover rates of proteins in various tissues of Japanese quail

1. 1. The effects of niacin deficiency on the relative turnover rates of proteins in various tissues of Japanese quail were investigated. 2. 2. The level of liver NAD was not affected by niacin deficiency whereas the level of pectoral muscle NAD was markedly reduced. 3. 3. In all dietary treatments the liver had the highest turnover rates of proteins, heart and brain had intermediate rates, and pectoral muscle had the lowest rates. 4. 4. Relative turnover rates of proteins in all tissues (particularly pectoral muscle) of the niacin deficient group were significantly higher than those of pair-fed control group, although there were no significant differences in turnover rate between pair-fed control and control groups. 5. 5. The high turnover rate of proteins in niacin deficiency was primarily attributed to enhanced degradation rate of proteins rather than enhanced synthesis rate of proteins. 6. 6. Optical density scanning (or densitometric) of water-soluble pectoral muscle proteins separated by isoelectric focusing revealed several additional minor protein bands between major protein bands in the niacin deficient group which were more pronounced in the acidic region of the gel. 7. 7. These results suggest that proteins with a low pI value in pectoral muscle of the niacin deficient animal are highly sensitive to protein degradation.

Experimental infection of mice with Toxocara canis larvae obtained from Japanese quails

The migration and distribution of Toxocara canis larvae in the tissues of Japanese quails, infected orally with 5 × 10 3 infective eggs, were studied, as well as the re-infectivity of these larvae in mice, inoculated with 50 larvae obtained from the liver of these quails. Post-infection, the highest concentrations of larvae were found to be present in the liver of quails while only a few migrated to other tissues like lungs, heart, muscle and brain. The migration and distribution of the larvae in the tissues of mice were studied by necropsy on days 6 and 12 postinfection. On both days the highest number of larvae, 11 and 10, were recovered from the carcase followed by six and seven from the leg muscles and four and eight from the brain, respectively. A few larvae were recovered from the liver, lungs and viscera. This implies that the larvae had a special affinity for the muscle and brain tissue of mice, unlike in the quails. The role of these larvae in relation to paratenism is discussed.

Infection of Japanese quail with Toxocara canis larvae and establishment of patent infection in pups

Migration and distribution of Toxocara canis larvae in the tissues of Japanese quail, infected orally with 5×10 3 infective eggs, and the establishment of patent infection from the quails to the definitive host, were studied. Larval yield at necropsy from various tissues and organs of quail varied from 4.72 to 7.54% of the infective eggs inoculated within the period 1–60 days post-infection (PI). The total number of larvae recovered on different days showed a gradual increase. The percent inoculum recovered at necropsy was highest on Day 60. Most of the larvae were found in the liver throughout the period and only a few migrated to other tissues, such as lung, heart, muscle and brain. The establishment of patent infections in the definitive host was studied by feeding the 15-day infected livers of Japanese quail (400 larvae) to Toxocara-free pups. Eggs first appeared in the faeces 38 days post-infection, the mean worm burden at necropsy was 87 and the percentage of infection established was 21.75%. Thus the role of Japanese quail as a paratenic host of T. canis is established.

Selenium-mediated biochemical changes in Japanese quails

The tissue uptake and distribution of injected [(75)Se]-sodium selenite as a variance with time and as influenced by dietary selenium status was followed in the tissues of Japanese quails,Coturnix coturnix japonica. Quails maintained on a low selenium semipurified (basal) diet and basal diets supplemented with 0.2 and 2.0 ppm selenium as sodium selenite were injected intraperitonially with(75)Se as sodium selenite (2.8 microcuries). The injected(75)Se was monitored in blood, liver, kidney, heart, and testis at 24, 72, and 144 h after injection. Maximal uptake of the injected(75)Se was observed in tissues of quails maintained on basal diet. The uptake of(75)Se in tissues in general was determined by the dietary Se status. Among the organs studied, kidney had the maximal level of(75)Se, 0.2 ppm (μg/g wet tissue) followed by liver, testis, and heart, but testis had the maximal level when the level per milligram of protein was considered, about 3.0 ng/mg protein, followed by liver, kidney, and heart. About 10-20% of the tissue(75)Se was located in the mitochondria and 50-60% in the post-mitochondrial supernatant fractions in all dietary Se levels. Significant incorporation of(75)Se in the mitochondrial membrane was observed. The percent distribution ratio between the membrane and matrix fractions of the mitochondria remained constant at all dietary Se levels which, in liver was 65∶35, in kidney 55∶45, and in testis 75∶25. However, in heart mitochondria, the distribution of(75)Se between membrane and matrix varied with dietary Se status, the ratio being 82∶18 in the basal group, and 72∶28 and 41∶59 in the 0.2 and 2.0 ppm Se-supplemented groups, respectively. This is indicative of a preferential uptake of(75)Se in the mitochondrial membrane in conditions of deficiency. About 40-60% of the mitochondrial membrane-associated(75)Se was released upon Triton treatment in all the organs. Of the membrane-bound(75)Se, about 10-15% was acid-labile in liver and kidney and 25% in the heart tissue. Possibilities of tissue specific roles, especially in the heart mitochondrial membrane-related processes, are indicated for selenium.

Lipocyte hyperplasia and sexual maturation of Japanese quail (Coturnix coturnix japonica)

1. Hyperplastic growth of adipose tissue in Japanese quail (Coturnix coturnix japonica) was examined in relation to sexual maturity to determine whether fat cell number is fixed in mature individuals of this species. 2. Total DNA concentrations in the lipid (lipocyte) and non-lipid (stroma) fractions of collagenase (EC 3.4.24.3)-digested abdominal (retroperitoneal) fat depots were determined on a chronological-age basis from 28 to 240 d of age. The in vivo incorporation of [methyl-3H]thymidine into DNA of both the lipocyte and stroma fractions of abdominal fat from both ad lib. and restricted-fed (75% of ad lib.) females was also examined at ages before and subsequent to sexual maturity. 3. In both males and females, significant increases in abdominal fat weights at ages beyond sexual maturity were associated with increased lipocyte DNA. Regardless of the feeding regimen and stage of maturity, substantial radioactivity was recovered from both the stromal and lipocyte fractions of abdominal fat when female quail were examined 24 h after the administration of tritiated thymidine. When examined 5 d post-injection, the majority of the radioactivity was contained in the lipid fraction of collagenase-digested adipose tissue. 4. Both the total DNA content of adipose tissue and the incorporation of tritiated thymidine into adipose tissue indicated that lipocyte hyperplasia contributes to postmaturational increases in fat deposition.