The use of the dog-whelk, Nucella lapillus, as an indicator of tributyltin (TBT) contamination

1987 ◽  
Vol 67 (3) ◽  
pp. 507-523 ◽  
Author(s):  
P. E. Gibbs ◽  
G. W. Bryan ◽  
P. L. Pascoe ◽  
G. R. Burt
Keyword(s):  
Vas Deferens ◽  
Nucella Lapillus ◽  
Male Characters ◽  
South West ◽  
Nassarius Obsoletus ◽  
South West England

The term ‘imposex’ was coined by Smith (1971) to describe the superimposition of male characters onto unparasitized and parasitized females of gonochoristic gastropods. In Nassarius obsoletus (Say) the development of imposex results in the female having one or more of the following characters: (1) a penis with a duct leading to (2) a vas deferens which passes back to the ventral channel of the capsule gland and (3) convolution of the normally straight gonadial oviduct (Smith, 1980). Imposex in the similarly gonochoristic Nucella lapillus (L.) was first noted by Blaber (1970) who found females with penis-like outgrowths in Plymouth Sound populations. Subsequent studies (Bryan et al. 1986; Gibbs & Bryan, 1986) have demonstrated that the incidence and intensity of imposex have since increased markedly in the same populations and that the phenomenon is widespread around south-west England.

Reproductive Failure in Populations of the Dog-Whelk, Nucella Lapillus, Caused by Imposex Induced by Tributyltin from Antifouling Paints

1986 ◽  
Vol 66 (4) ◽  
pp. 767-777 ◽  
Author(s):  
P. E. Gibbs ◽  
G. W. Bryan
Keyword(s):  
Vas Deferens ◽  
Early Stage ◽  
Premature Death ◽  
Intermediate Stage ◽  
Reproductive Failure ◽  
Nucella Lapillus ◽  
Egg Capsules ◽  
Male Characters ◽  
High Incidence ◽  
Declining Populations

The development of male characters, notably a penis and a vas deferens, on the female (the phenomenon of ‘imposex’) of the dog-whelk, Nucella lapillus, is described. Three stages are recognized: an ‘early’ stage involving the formation of a vas deferens and a small penis, an ‘intermediate’ stage characterized by the enlargement of the female penis to a size approaching that of the male and a ‘late’ stage during which the female opening (vulva) is occluded by overgrowth of vas deferens tissue. This blockage of the pallial oviduct prevents the release of egg capsules and renders the female sterile. The extent and cause of such reproductive failure is evident from the high incidence of females containing aborted capsules in declining populations close to sources of tributyltin (TBT) contamination. These same populations comprise fewer females than expected and it would appear that the accumulation of aborted capsules within the pallial oviduct eventually causes the premature death of the female.

A Comparison of the Effectiveness of Tri-N-Butyltin Chloride and Five other Organotin Compounds in Promoting the Development of Imposex in the Dog-Whelk, Nucella Lapillus

1988 ◽  
Vol 68 (4) ◽  
pp. 733-744 ◽  
Author(s):  
G. W. Bryan ◽  
P. E. Gibbs ◽  
G. R. Burt
Keyword(s):  
Vas Deferens ◽  
Sea Water ◽  
Water Concentration ◽  
Conclusive Evidence ◽  
Genital Papilla ◽  
Rocky Shores ◽  
Nucella Lapillus ◽  
The United Kingdom ◽  
Penis Size ◽  
Nassarius Obsoletus

Populations of the common dog-whelk Nucella lapillus (L.) are declining or have already disappeared at many sites on rocky shores around the United Kingdom (Bryan et al. 1986). There is conclusive evidence that this is caused mainly by tributyltin (TBT) compounds leached from ships' antifouling paints (Bryan et al. 1987). These compounds impose male sexual characters (or imposex) on female N. lapillus. Other stenoglossan gastropods including Nassarius obsoletus Say (Smith, 1981a) and Ocenebra erinacea (L.) (Féral & Gall, 1982) are similarly affected by TBT. The intensity of expression of imposex in N. lapillus can generally be related to the sea water concentration of TBT. The appearance of a small penis and the partial development of a vas deferens first occurs at TBT concentrations below 0.5 ng/1 (as tin), although reproduction appears to be unaffected at this level. At 1–2 ng Sn/1 penis size is markedly increased and in some females proliferation of vas deferens tissue overgrows the genital papilla, thus sterilizing the animal. At slightly higher concentrations virtually all females become sterilized and at around 10 ng Sn/1 oogenesis is suppressed and spermatogenesis initiated (Gibbs, Pascoe & Burt, 1988). Since development is direct and there is no planktonic stage, N. lapillus has a very limited capacity for dispersion: thus the sterilization of females heralds the almost certain decline of so affected populations (Gibbs & Bryan, 1986).

Appearance of a genetically-based pollution resistance in a marine gastropod, Nucella lapillus, in south-west Brittany: a new case of Dumpton syndrome

2008 ◽  
Vol 88 (7) ◽  
pp. 1475-1479 ◽  
Author(s):  
M. Huet ◽  
N. Le Goïc ◽  
P.E. Gibbs
Keyword(s):  
Vas Deferens ◽  
Molecular Probe ◽  
Normal Male ◽  
Nucella Lapillus ◽  
South West ◽  
Advanced Stages ◽  
Male Sex ◽  
First Time ◽  
Tbt Pollution ◽  
Female Carriers

Most neogastropod species exhibit masculinization of the female when subject to tributyltin (TBT) pollution (a process known as ‘imposex’). To date, the dog-whelk Nucella lapillus is seemingly unique in having a genetic deficiency (termed Dumpton syndrome or DS) that disrupts the development of normal male sex organs, its presence being readily recognizable by the underdevelopment, or non-development (aphally), of the penis, and incomplete formation (non-closure) of the vas deferens, causing a split prostate. In highly contaminated conditions, female carriers of DS can be identified by a lesser degree of masculinization (notably aphally): they escape sterilization caused by the advanced stages of imposex. To date, DS has only been reported in areas with high TBT pollution which induces sterilization of normal females (i.e. non DS-affected females). DS is now, for the first time, observed at some locations where present TBT levels are low and some normal females lack penis development. In such conditions it is not possible to discriminate normal from DS-affected females using aphally. As DS-affected females must be discarded from the calculation of the imposex bioindicators to monitor TBT pollution, indirect tools such as molecular probe are now needed to further survey those areas where DS and TBT pollution may interact as, for example, in south-west Brittany.

The Decline of the Gastropod Nucella Lapillus Around South-West England: Evidence for the Effect of Tributyltin from Antifouling Paints

1986 ◽  
Vol 66 (3) ◽  
pp. 611-640 ◽  
Author(s):  
G. W. Bryan ◽  
P. E. Gibbs ◽  
L. G. Hummerstone ◽  
G. R. Burt
Keyword(s):  
Nucella Lapillus ◽  
The South ◽  
Antifouling Paints ◽  
South West ◽  
Male Sex ◽  
South West England

A survey of the gastropod Nucella lapillus around the south-west peninsula of England has revealed that the incidence of ‘imposex’, the induction of male sex characters in the female, is widespread, that all populations are affected to some degree and that the phenomenon is most prevalent along the south (Channel) coast. Populations close to centres of boating and shipping activity show the highest degrees of imposex, especially those within the vicinities of the Helford, Fal, Salcombe and Dart estuaries and in Plymouth Sound and Tor Bay. Within Plymouth Sound the degree of imposex increased markedly between 1969 and 1985, coinciding with the introduction and increasing usage of antifouling paints containing tributyltin (TBT) compounds.

TBE in United Kingdom

2020 ◽  
Keyword(s):  
United Kingdom ◽  
Clinical Disease ◽  
England And Wales ◽  
Probable Case ◽  
The United Kingdom ◽  
South West ◽  
Louping Ill ◽  
The Uk ◽  
North And South ◽  
South West England

Until 2019, TBE was considered only to be an imported disease to the United Kingdom. In that year, evidence became available that the TBEV is likely circulating in the country1,2 and a first “probable case” of TBE originating in the UK was reported.3 In addition to TBEV, louping ill virus (LIV), a member of the TBEV-serocomplex, is also endemic in parts of the UK. Reports of clinical disease caused by LIV in livestock are mainly from Scotland, parts of North and South West England and Wales.4

scholarly journals Diocesan Licensing and Medical Practitioners in South-West England, 1660–1780

2004 ◽  
Vol 48 (1) ◽  
pp. 49-68 ◽  
Author(s):  
Ian Mortimer
Keyword(s):  
Early Modern ◽  
Specific Context ◽  
Medical Practitioners ◽  
Medical Expertise ◽  
North West ◽  
The North ◽  
Decentralized Trade ◽  
South West ◽  
The Many ◽  
South West England

The licensing of provincial surgeons and physicians in the post-Restoration period has proved an awkward subject for medical historians. It has divided writers between those who regard the possession of a local licence as a mark of professionalism or proficiency, those who see the existence of diocesan licences as a mark of an essentially unregulated and decentralized trade, and those who discount the distinction of licensing in assessing medical expertise availability in a given region. Such a diversity of interpretations has meant that the very descriptors by which practitioners were known to their contemporaries (and are referred to by historians) have become fragmented and difficult to use without a specific context. As David Harley has pointed out in his study of licensed physicians in the north-west of England, “historians often define eighteenth-century physicians as men with medical degrees, thus ignoring … the many licensed physicians throughout the country”. One could similarly draw attention to the inadequacy of the word “surgeon” to cover licensed and unlicensed practitioners, barber-surgeons, Company members in towns, self-taught practitioners using surgical manuals, and procedural specialists whose work came under the umbrella of surgery, such as bonesetters, midwives and phlebotomists. Although such fragmentation of meaning reflects a diversity of practices carried on under the same occupational descriptors in early modern England, the result is an imprecise historical literature in which the importance of licensing, and especially local licensing, is either ignored as a delimiter or viewed as an inaccurate gauge of medical proficiency.

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