Wool follicle development in New Zealand Romney and N-type sheep. 3. Diameters of follicles and fibres

1959 ◽  
Vol 10 (1) ◽  
pp. 108 ◽  
Author(s):  
SK Stephenson
Keyword(s):  
New Zealand ◽  
Pleiotropic Effect ◽  
Primary Effect ◽  
N Gene ◽  
Follicle Development ◽  
Primary Follicle ◽  
Fibre Size ◽  
Wool Follicle ◽  
Follicle Size

The diameters of the primary and secondary follicles hare been measured in N type and New Zealand Romney foetuses. It is shown that the primary effect of the N gene is on the primary follicle papilla and fibre size, not on overall follicle size A secondary pleiotropic effect is on the primary follicles, which Increase in diameter as a result of growing large fibres There do not appear to be any other effects of the dominant N gene up to 126 days after conception, either on the follicle population or on the growth of the foetus.

Wool follicle development in the New Zealand Romney and N type sheep. V. The pre-natal relationships between growth, skin expansion, and primary follicle number

1959 ◽  
Vol 10 (3) ◽  
pp. 453 ◽  
Author(s):  
SK Stephenson
Keyword(s):  
New Zealand ◽  
Surface Area ◽  
Linear Growth ◽  
The Body ◽  
Follicle Development ◽  
Competition Effect ◽  
Primary Follicle ◽  
Skin Expansion ◽  
Wool Follicle

A method is presented for estimating changes in primary follicle number on different regions of the body of the sheep foetus from linear growth measurements and primary follicle density determinations. The major factor controlling the initiation of new primary follicle anlagen on different regions is shown to be rate of skin expansion, and therefore it appears probable that there is a competition effect between anlagen during this phase of development. After allowance is made for area increases, there are still real differences between regions in the rates of initiation of primary anlagen. There is also evidence that, during the period of primary anlagen initiation, foetuses with a greater surface area have a greater total number of primary anlagen.

Wool follicle development in the New Zealand Romney and N type sheep. II. Follicle population density during foetal development

1958 ◽  
Vol 9 (1) ◽  
pp. 138 ◽  
Author(s):  
SK Stephenson
Keyword(s):  
New Zealand ◽  
Population Density ◽  
Subsequent Development ◽  
The Body ◽  
Limiting Factor ◽  
Follicle Development ◽  
Primary Follicle ◽  
Foetal Development ◽  
Secondary Follicle ◽  
The Face

Quantitative aspects of follicle initiation and development have been studied in a series of N-type and New Zealand Romney foetuses. Density of the follicle population and ratios of secondary to primary follicles were examined on 13 positions of the body which covered the main wool-bearing areas, the face and head, and the limbs. Primary follicle development is initiated first on the head and limbs and throughout subsequent development these regions are most advanced. Primary follicle density reaches a maximum between 75 and 90 days of foetal age, after which it decreases as a result of skin growth. Secondary follicle initiation is more rapid on the wool-bearing areas of the body, and higher ratios of secondary to primary follicles are recorded from these regions. No real differences have been found between N-type and New Zealand Romney foetuses in population density of the different follicle types at any age or in the number of secondary follicles developed per primary follicle. The growth of larger primary fibres and follicles in N-type foetuses is not accompanied by, and does not result from, a lower density of primary follicles. There does not appear to be any marked relation between the decreasing density of primary follicles after 90 days of foetal age and the initiation of secondary follicle anlagen. This fact, and the absence of any differences in the number of secondary anlagen formed per primary follicle in N-types, suggest that crowding in N-types is not a limiting factor in the formation of secondary follicle anlagen.

Wool follicle development in the New Zealand Romney and N type sheep. I. The relationships of development to age in the New Zealand Romney and N type sheep foetuses and a comparison with results obtained from the Merino

1957 ◽  
Vol 8 (4) ◽  
pp. 371 ◽  
Author(s):  
SK Stephenson
Keyword(s):  
New Zealand ◽  
Least Squares ◽  
Linear Relationship ◽  
Population Studies ◽  
Regression Line ◽  
The Body ◽  
Follicle Development ◽  
Method Of Least Squares ◽  
Rate Of Development ◽  
Wool Follicle

The development of the follicle population in New Zealand Romney and N-type sheep foetuses has been studied by comparing stages of development at different ages, using the method developed by Carter and Hardy (1947) and Hardy and Lyne (1956). Their scale has been altered so as to give a linear relationship with age, and a regression line has been fitted to the data by the method of least squares. Analysis of the N-type and New Zealand Romney mating groups and a comparison with the Merino data given by Carter and Hardy (1947) show that no marked or consistent differences occur in the age at which different stages of follicle development are completed or in the rate of development of the follicle population. Studies of different positions on the body agree with the findings of other workers that development begins first on the head and limbs and later over the trunk. Between positions the correlation between the age at which follicle development begins and the rate of development after initiation is not significant.

Gene expression profiling of ovine skin and wool follicle development using a combined ovine - bovine skin cDNA microarray

2005 ◽  
Vol 45 (8) ◽  
pp. 867 ◽  
Author(s):  
B. J. Norris ◽  
N. I. Bower ◽  
W. J. M. Smith ◽  
G. R. Cam ◽  
A. Reverter
Keyword(s):  
Gene Expression ◽  
Gene Expression Profiling ◽  
Cdna Microarray ◽  
Expression Profiling ◽  
Fibre Diameter ◽  
Follicle Development ◽  
Primary Follicle ◽  
Fetal Sheep ◽  
Molecular Control ◽  
Wool Follicle

Low fibre diameter and high fleece weight are important determinants of the economic value of the Merino fleece. The combination of these traits is found in Merino sheep with high follicle densities resulting from a high secondary to primary follicle ratio. Morphological stages in the development of primary and secondary follicles of fetal sheep skin have been well described. We have used gene expression profiling of fetal skin to identify genes that may be important in controlling these follicle developmental processes. A combined ovine (2.3 K) and bovine (6.14 K) cDNA microarray of 2 fetal and 1 adult stage skin tissues was constructed to compare gene expression levels between fetal day 82, day 105, day 120 and adult sheep skin developmental stages. The transcript profile resulted in 238 differentially expressed array elements relative to the adult expression, which represented 132 unique genes. These clustered into 50 up- and 82 down-regulated genes and distinct gene ontologies including structural constituents, phosphate transport, signal transduction and organogenesis. Northern blot analysis of 2 selected genes, S100A7LI and TAGLN, validated the microarray results. This list of genes contains candidates of interest for further investigation into the molecular control of wool follicle development.

Pre- and post-natal wool follicle development and density in sheep of five genotypes

1996 ◽  
Vol 126 (3) ◽  
pp. 363-370 ◽  
Author(s):  
J. E. Hocking Edwards ◽  
M. J. Birtles ◽  
P. M. Harris ◽  
A. L. Parry ◽  
E. Paterson ◽  
...  
Keyword(s):  
New Zealand ◽  
Similar Pattern ◽  
Critical Period ◽  
The Other ◽  
Follicle Development ◽  
Physiological Factors ◽  
Factors Affecting ◽  
Wool Follicle ◽  
Follicle Maturation ◽  
Skin Samples

SUMMARYThe pre-natal and post-natal development of wool follicles in sheep of five genotypes with contrasting wool types was examined to provide data on which to base studies of physiological factors affecting wool type via follicle development. This study was conducted following Autumn mating in 1992 at Palmerston North, New Zealand (40° S, 176° E). The rate and timing of follicle development in midside skin samples from Romney, Merino, Merino × Romney (M × R), Drysdale and Wiltshire foetuses and lambs collected at weekly intervals from days 76 to 143 of gestation and 1, 3, 7, 12 and 32 weeks after birth were examined.Primary (P) follicle density had a similar pattern of development in each of the genotypes, although the Merino had a significantly greater density of P follicles than the other genotypes. There was a difference in the rate of P follicle maturation between genotypes with the Drysdale, Wiltshire and M × R completing P follicle maturation before the other two genotypes. However, the majority of P follicles in all genotypes were producing fibres by 111 days of gestation. It was concluded that the small differences in the density and time of development of the P follicles could not cause the differences in wool type between genotypes.The pattern of development of the secondary (S) follicle population was examined by comparing S: P ratios. The initiation of S follicles began at similar ages in the five genotypes, but initiation was completed earlier in the Romney, Drysdale and Wiltshire than in the Merino and M × R, as indicated by a significant genotype by age interaction (P < 0·001). There was no difference between genotypes in S:P ratio from 90 to 104 days of gestation. The S:P ratio of the Romney, Drysdale and Wiltshire did not change significantly from 104 days of gestation until the end of the study, indicating that few S follicles were initiated in these genotypes after 104 days of gestation. The M × R data showed a significant increase in S:P ratio until 119 days of gestation and the Merino S:P ratio increased until 126 days of gestation.The period between days 90 and 125 of gestation was identified as being the critical period for the development of different follicle populations in Merino and non-Merino genotypes and it is this period which should be the focus for studies to determine physiological factors controlling secondary follicle development.

scholarly journals Proteomic Analysis Identifies Potential Markers for Chicken Primary Follicle Development

Animals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1108
Author(s):  
Armughan Ahmed Wadood ◽  
Jingyuan Wang ◽  
Liping Pu ◽  
Qaisar Shahzad ◽  
Muhammad Waqas ◽  
...  
Keyword(s):  
Proteomic Analysis ◽  
Egg Production ◽  
Potential Role ◽  
Protein Localization ◽  
Follicular Development ◽  
Egg Laying ◽  
Follicle Development ◽  
Phosphate Binding ◽  
Primary Follicle ◽  
Mannose Metabolism

Follicles’ development in chicken imparts a major impact on egg production. To enhance the egg-laying efficiency, comprehensive knowledge of different phases of follicular development is a prerequisite. Therefore, we used the tandem mass tag (TMT) based proteomic approach to find the genes involved in the primary follicular development of chicken. The primary follicles were divided into two groups—small primary follicles (81–150 μm) and developed primary follicles (300–500 μm). Differential expression analysis (fold change > 1.2, p-value < 0.05) revealed a total of 70 differentially expressed proteins (DEPs), of which 38 were upregulated and 32 were downregulated. Gene ontology (GO) enrichment analysis disclosed that DEPs were intricate with cellular protein localization, the establishment of protein localization, and nucleoside phosphate-binding activities. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment pathway indicated the involvement of DEPs in different metabolic pathways such as glycolysis, pyruvate metabolism, galactose metabolism, and fructose and mannose metabolism. The current proteomic analysis suggested suitable markers such as Anxa2, Pdia3, and Capzb, which may serve as a potential role for primary follicle development. The present study provides the first insight into the proteome dynamics of primary follicle development and would play a potential role for further studies in chicken to improve egg productivity.

The dominant N gene in New Zealand Romney sheep

1955 ◽  
Vol 6 (5) ◽  
pp. 725 ◽  
Author(s):  
FW Dry
Keyword(s):  
New Zealand ◽  
Small Area ◽  
Genetic Basis ◽  
Dominant Gene ◽  
The Body ◽  
N Gene ◽  
Extreme Variation ◽  
Ram Lambs ◽  
The One ◽  
Different Sources

The existence of the dominant N gene, derived from two different sources, has been established by monogenic ratios. The gene is variable in expression in the heterozygote, and is pleiotropic. Horns are a sex-influenced expression of this gene, being dominant in males and recessive in females, with exceptions of the order of one in 10 in both sexes. There are hints that the exceptions in rams have a genetic basis, and strong evidence that this is so in heterozygous ewes, a dominant gene, F, variable in expression, being postulated. In the birthcoat of heterozygotes the expression of the N gene varies over a range as wide as is possible. There is extreme variation in halo-coverage over the body in animals of N-abundance on the back, and all halo-grades, from borderline-N to no-halo, are found in the one-sixth of heterozygotes less than N-grade. There is evidence that some part in causing the heterozygote to be less than N-grade is played by genes which reduce the abundance of halo-hairs on the main area of the body in non-N lambs. Possibly one dominigene, not linked with N, is powerful in the heterozygote. Heterozygous dominant N-grade lambs, with very few exceptions, can be distinguished from homozygotes in having halo-hair abundance reduced below that of N-grade at the anterior end of the body, at least in a small area behind the shoulder which is called the shoulder patch. The absence of the shoulder patch in heterozygotes has a genetic basis. Very occasionally there appears to be overlap between the two genotypes in the opposite direction. Recently a very small number of lambs thought to be homozygotes have been a little short of full halo-hair abundance on the shoulder patch on either one or both sides of the body. It is also of some help in distinguishing the genotypes that homozygous ram lambs have lumps in the horn positions, while heterozygous ram lambs frequently have no lumps at birth. On the average homozygous fleeces are more coarsely hairy than heterozygous, and contain more secondary kemp. In setting out the facts from which the above circle of conclusions is drawn it is sometimes convenient to make use at an earlier stage of something which is not proved until later. This applies especially to distinguishing homozygote and heterozygote.

The recessive N gene in New Zealand Romney sheep

1955 ◽  
Vol 6 (6) ◽  
pp. 833 ◽  
Author(s):  
FW Dry
Keyword(s):  
New Zealand ◽  
Small Proportion ◽  
Fibre Type ◽  
Genetic Basis ◽  
Dominant Gene ◽  
Great Majority ◽  
The Other ◽  
N Gene ◽  
Know How

The recessive N gene, nr, is demonstrated by monogenic ratios. For the most part nr/nr characters are intermediate between those of N/N and N/+. About a sixth of nr/nr lambs have no shoulder patch, and in certain fibre type details, and in hairiness, nr/nr animals tend to be intermediate between the two dominant-N genotypes. On the other hand, all nr/nr ewes have been hornless; a few have had horn-lumps, one scum By contrast, about one N/+ ewe in 10 grows horns. All the nr/nr rams reared to 1 year, except one with scurs, have grown horns. Carrier (+/nr) sheep have birthcoats which we do not know how to distinguish from those of ordinary Romneys, though there is evidence that one dose of nr increases halo-abundance on the back slightly. A few +/nr lambs have been grade VI. Just a few +/nr sheep have fleeces as hairy as the average N/+. A quarter or more of the +/nr rams have had horns, mostly small, at 4 months, and nearly all the others have had scurs. The genes N and nr are not allelic, but may be linked. Because the sheep has 26 pairs of autosomes free assortment seems more probable. In general the characterization of sheep deemed N/+.+/nr is intermediate between that of N/N.+/+ and N/+.+/+. The noticeable difference between N/+.+/nr and +/+ nr/nr is the more powerful growth of horns in the double heterozygotes. An analysis of breeding results from N/+.+/nr sheep indicates that the great majority of N/+.nr/nr animals of both sexes have the horn and halocoverage characters of homozygous dominant-N's. In N/+.+/nr, some ewes have horns, and the shoulder patch is absent about as often as in nr/nr. The frequencies of these characters in N/+.+/nr are applied in showing that the genetic basis of horns in ewes, and the genetic basis of full halo-coverage, in heterozygotes of the dominant-N stock are different; and that it is not the gene nr which makes horns grow in the dominant-N heterozygous ewes; and one piece of evidence suggests that it is not the nr gene that determines absence of shoulder patch in the birthcoats of the dominant-N stock. It is concluded that if the dominant-N stock is not completely free from nr, that gene has only the same sort of frequency as in the Romney breed. Matings made as +/+.nr/nr X +/+.+/+, the latter no-halo ewes, from flocks outside the College, or if bred at the College unrelated to any N-type sheep, have given a small proportion of N-grade lambs. It now appears that at least most of these lambs, called 'dominoes', have received one dose of a dominant gene for N-grade, probably the gene N, from the no-halo parent. One no-halo ewe from an outside source had an N-grade son, proved nr/nr, by a domino ram, the dam thus being shown to carry the gene nr.

Wool follicle morphology and cell proliferation in New Zealand Romney sheep: a seasonal comparison of fleeceweight-selected and control rams

1994 ◽  
Vol 45 (4) ◽  
pp. 769 ◽  
Author(s):  
SA Holle ◽  
PM Harris ◽  
AS Davies ◽  
MJ Birtles
Keyword(s):  
New Zealand ◽  
Three Dimensional ◽  
Dermal Papilla ◽  
Proliferating Cells ◽  
Root Sheath ◽  
Inner Root Sheath ◽  
Dimensional Measurements ◽  
Wool Follicle ◽  
Seasonal Influences ◽  
And Control

Effects of selection for high fleeceweight in the New Zealand Romney sheep were investigated in relation to the morphology of individual follicles and changes in the germinative cell population of the follicle bulb. Two-year-old Romney rams, 10 from each of two selection lines (Massey University fleeceweight-selected (FWT) and control (CLT) flock), were run together on pasture for a period from June to early December. At three times during this observation period (June, August and November) skin samples were taken from their midside flanks after local injection of bromodeoxyuridine (BrdU), to assess proliferation of bulb cells and several dimensional measurements of the follicle bulb and dermal papilla. FWT sheep had larger follicle dimensions than CLT sheep during winter and summer, with a greater number of proliferating bulb cells. Both flocks showed a seasonal change in follicle size, with a decline during winter, but the size of the dermal papilla was less affected than the germinative tissue area. Measurements of proliferation density (number of proliferating cells per area/volume of bulb tissue) suggest that changes in proliferation density do not contribute to flock differences in fleece production. However, during summer, FWT showed a 40% advantage over CLT sheep in hourly cell production based on data from three dimensional follicle bulb extrapolation. The different genotypes showed variations in width, as well as area of cortex and inner root sheath (IRS), measured across the top of the dermal papilla. The expression of these differences was further enhanced through seasonal influences, suggesting that there is an interaction between genetic/flock influences and seasonal influences on cell distribution to cortex and inner root sheath.

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