Male Fur Research Articles

Vagrant sub-Antarctic fur seal at tropical Ascension Island, South Atlantic Ocean

Knowledge of extra-limital movements of seals improves our understanding of species’ dispersal and dispersion abilities and patterns, and perhaps environmental changes. Canvassing and internet literature searches revealed the sighting of a vagrant adult male sub-Antarctic fur seal Arctocephalus tropicalis on the coast adjacent to George Town (7° 56′ S, 14° 25′ W), Ascension Island, in 2010. Although finer details of the sighting are sketchy, this is the first sighting of any seal at Ascension Island, and the northernmost sighting on record for the species on the mid-Atlantic Ridge islands. The likely source of the vagrant is the population at Gough Island (40° 20′ S, 9° 54′ W) some 3624 km further south in the Atlantic. The vagrant likely moved westward from Gough Island to the Brazilian coast, then northwards in coastal waters, eventually reaching Ascension Island.

Stalked barnacles on an adult male sub-Antarctic fur seal at Inaccessible Island, Tristan da Cunha

An adult male sub-Antarctic fur seal, Arctocephalus tropicalis, on Inaccessible Island in the Tristan da Cunha archipelago (TdC), was observed infested with goose barnacles, likely Lepas australis. Although adult females have been recorded to carry goose barnacles, this is the first record from an adult male at a breeding island. Males remain at sea throughout winter, so it is not clear why there are not more records of goose barnacles attached to their pelage.

481. CRISPR/Cas9-Mediated In Vivo Genome Editing to Correct the OTC spfash Mutation in Newborn Mice

Many genetic liver diseases, including OTC deficiency, present in newborns with repeated, often lethal, metabolic crises. Adeno-associated virus (AAV) neonatal gene therapy in this setting would require multiple vector administrations to maintain the therapeutic effects because the non-integrating genome is lost as developing hepatocytes proliferate. As such, we reasoned that newborn liver may be an ideal setting for AAV-mediated gene correction using CRISPR/Cas9, a powerful genome-editing tool consisting of the Cas9 nuclease and a single-guide RNA (sgRNA). We developed a strategy using an AAV vector with high liver tropism (AAV8) to correct the point mutation in newborn spfash mice using Cas9 enzyme from Staphylococcus aureus (SaCas9). An animal model of OTC deficiency, the male sparse fur ash (spfash) mouse, has a G-to-A point mutation at the donor splice site at the end of exon 4 of the OTC gene, which leads to abnormal splicing and a 20-fold reduction in OTC mRNA and protein.We developed a two-vector approach to incorporate all 3 components of CRISPR/Cas9 into AAV. Vector 1 expresses the SaCas9 gene from a liver-specific TBG promoter, while vector 2 contains both the sgRNA1 sequence expressed from a U6 promoter and the 1.8 kb donor OTC DNA sequence. Spfash pups were injected intravenously on postnatal day 2 with mixtures of vector 1 and vector 2 and subsequently evaluated for indel (insertion and deletion) formation and functional correction of the spfash mutation. Following gene correction (3 and 8 weeks), indels were detected by deep sequencing in 31% of OTC alleles, and HDR-based correction of the G-to-A mutation was observed in 10% of OTC alleles. Liver sections were analyzed by immunohistochemistry for OTC expression, showing 15% OTC-positive cells at 3 weeks and 13% at 8 weeks. Direct measurements of OTC enzyme activity from liver homogenates and OTC mRNA from total cellular RNA from liver revealed similarly high levels of correction in treated animals. We further assessed the impact of gene correction on the clinical manifestations of OTC deficiency by evaluating the tolerance of spfash mice to a one-week course of high-protein diet. Spfash mice treated with the gene-editing vectors had significantly lower plasma ammonia levels and showed a survival improvement as compared with untreated spfash mice. This study provides convincing evidence for efficacy in an authentic animal model of a lethal human metabolic disease following in vivo genome editing.

Gendering Fashion, Fashioning Fur: On the (re)production of a Gendered Labor Market within a Craft Industry in Transition

What are the implications of the new economy for gender equality in labor markets? Does an economy that privileges ‘immaterial’ labor (the production of ideas) over ‘material’ labor (the manual production of goods) signal the possibility for greater labor market inclusion? Building on critical accounts of the new economy, I examine the bases for continued gender hierarchies through an analysis of the contemporary restructuring of the fur industry in Canada. As a traditional craft industry, fur has sought to adapt to new-economy imperatives by incorporating ‘immaterial’ labor in the form of fashion design. However, these efforts have been limited, as the (predominantly male) fur manufacturers have sought to retain authority in a changing economy by integrating design as a subordinate activity—a subordination made possible through a coding of design as feminine and through the deployment of the fashion designer as a flexible source of labor. Drawing on interviews with manufacturers, designers, and other industry actors, I analyze how new-economy imperatives intersect with local institutional practices and ideologies to reproduce a gendered labor market.

Vagrant Subantarctic fur seal at Cape Shirreff, Livingston Island, Antarctica

A vagrant adult male Subantarctic fur seal Arctocephalus tropicalis was observed among Antarctic fur seals A. gazella at Cape Shirreff, Livingston Island, Antarctica, which is located to ~4,190 and ~5,939 km from the nearest breeding colonies of Subantarctic fur seals. Although the colony of origin of this animal and the reason for its movement outside its distribution range are unknown, this sighting shows the high dispersal capacity of this species and provides an insight into possible changes in its distribution. Although this vagrant was not observed with females Antarctic fur seal, news sightings in the future could result in viable hybrid, and introgressive hybridization could represent a threat for Cape Shirreff population recovery, if still the population way to go to recover to presailing levels.

Vocal repertoire of South American fur seals, Arctocephalus australis: structure, function, and context

We describe the vocal repertoire of male and female South American fur seals (Arctocephalus australis) breeding at Punta San Juan, Peru, the first such description for any member of the genus. We distinguished 11 call types, which we grouped into four functional classes: investigative, threat, submissive, and affiliative calls. Barking is used during non-agonistic investigation of other individuals. Threat calls of South American fur seals show gradation of structure, form, and apparent meaning, and are grouped into two series: nontonal or respiratory sounds, and pulsed or guttural sounds that sometimes include a terminal tonal component. This might be adaptive in enabling display behavior to be flexible in agonistic situations, allowing participants to interpret situations on the basis of contextual cues and their own physical ability and experience. In contrast, vocal displays such as submissive, full-threat, and affiliative calls tend to have a discrete acoustic structure. Of these, full-threat, female-attraction, and pup-attraction calls share acoustic characteristics: all are long, loud calls composed of both pulsed and tonal components, and show sufficient variation to allow individual recognition. We attempt to establish a base line for standardizing nomenclature and acoustic analysis, to facilitate further comparative research on the vocal repertoire of Arctocephalus species.

Skull morphometrics of male Subantarctic fur seals (Arctocephalus tropicalis) from Marion and Gough Islands

Skull morphometrics of two populations of Subantarctic fur seal (Arctocephalus tropicalis) were compared in order to identify possible geographic variation as an indicator of gene flow between the populations, as well as a potential tool to identify the source of vagrant seals. Nineteen metric variables were recorded from skulls of adult male seals from Marion Island (n=31) and Gough Island (n=41). Comparative univariate and multivariate statistical analyses conducted on the two population samples included standard statistics (mean, standard deviation, coefficient of variation, range), multivariate analysis of variance, stepwise discriminant function analysis, cluster analysis and principal component analysis. No significant separation between the two island groups, based on cranial characteristics of adult males, was found. These findings suggest that gene flow is occurring between these populations.We conclude that skull morphometrics cannot be used to identify the origins of vagrant Subantarctic fur seals.

Aggressive behaviour of an adult male Cape fur seal (Arctocephalus pusillus pusillus) towards a great white shark (Carcharodon carcharias)

This is a report of a marine predator (the white shark) being threatened by a member of the species on which it preys (a male Cape fur seal). Although these events may be rarely observed or occur infrequently, they may have important implications for the predator and its prey.We suggest that shark mobbing by adult male Cape fur seals is adaptive for the reduction of risk of predation by sharks. Mobbing of sharks is likely to alert conspecifics to the presence of a predator, and/or reduce the shark's hunting motivation near the mobbing site.

Seasonal and age-related changes in the micro-anatomy of the prostate gland of the Subantarctic fur seal,Arctocephalus tropicalis

The prostate glands of male Subantarctic fur seals Arctocephalus tropicalis , taken at Gough Island (40°20'S, 09°54'W) between November 1977 and October 1978, were examined. Significant changes in the mass of the prostate, the diameter of the alveoli and height of the secretory epithelium precede the breeding season and support the fact that A. tropicalis is a seasonal breeder. Peak activity of the prostate is reached during November-January. We propose that seasonal changes in the prostate gland, and in male reproductive activity in general, may be cued by changing photoperiod. Micro-anatomical features of the prostate of the male Subantarctic fur seal differ between different age groups. Peak prostate mass, alveoli diameter and secretory cell height indicate that Subantarctic fur seal males reach full adulthood at 10–11 years of age.

Reproduction in the male Cape fur seal Arctocephalus pusillus pusillus: age at puberty and annual cycle of the testis

Reproduction in the male Cape fur seal Arctocephalus pusillus pusillus: age at puberty and annual cycle of the testis

Dispersal of male and female Antarctic fur seals (<i>Arctocephalus gazella</i>)

Dispersal of male and female Antarctic fur seals (<i>Arctocephalus gazella</i>)

Further evidence for a separate enzymic entity for the synthesis of homocitrulline, distinct from the regular ornithine transcarbamylase.

Differential digitonin extraction of rat liver mitochondria and of mitochondria of livers of affected and unaffected male sparse fur mice released a lysine transcarbamylase activity from the mitochondria at a digitonin to protein ratio in between that for myokinase and glutamate dehydrogenase, but at a slightly lower ratio than the ornithine transcarbamylase activity. Homocitrulline formation by isolated rat liver mitochondria is independent of the uptake of lysine by mitochondria as evidenced by the insensitivity of homocitrulline formation to changes in the matrix pH, in contrast to citrulline formation from ornithine. High-performance liquid chromatography separates the lysine transcarbamylase activity from the ornithine transcarbamylase activity. It is concluded that the lysine transcarbamylase activity is localized outside the inner mitochondrial membrane.

A Male Guadalupe Fur Seal on San Nicolas Island, California

A Male Guadalupe Fur Seal on San Nicolas Island, California