| viral tail proteins | Proteins found in the tail sections of DNA and RNA viruses. It is believed that these proteins play a role in directing chain folding and assembly of polypeptide chains. (12 Dec 1998) |
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| comet tail sign | In chest radiology, the curved appearance of pulmonary arteries and veins associated with round atelectasis, fibrosis associated with organizing pleurisy. Synonym: comet tail sign. (05 Mar 2000) |
| poly A tail | <molecular biology> A sequence of adenine nucleotides that get added to the 3' end of some primary transcript messenger RNA molecules in eukaryotes during post-transcriptional processing. The added tail is believed to confer stability to the molecule. Histone mRNA do not have poly A tail. The poly A tail is added post transcriptionally to the primary transcript as part of the nuclear processing of RNA yielding hnRNAs with 60-200 adenylate residues in the tail. In the cytoplasm the poly A tail on mRNAs is gradually reduced in length. The function of the poly A tail is not clear but it is the basis of a useful technique for the isolation of eukaryotic mRNAs. The technique uses an affinity column with oligo(u) or oligo(dT) immobilised on a solid support. If cytoplasmic RNA is applied to such a column, poly A rich RNA (mRNA) will be retained. (13 Nov 1997) |
| hare's-tail | <botany> A kind of grass (Eriophorum vaginatum). See Cotton grass, under Cotton. Hare's-tail grass, a species of grass (Lagurus ovatus) whose head resembles a hare's tail. Source: Websters Dictionary (01 Mar 1998) |
| sperm tail | The posterior, filiform part of spermatozoa, which provides sperm motility. (12 Dec 1998) |
| split-tail | <zoology> A california market fish (Pogonichthys macrolepidotus) belonging to the Carp family. The pintail duck. Source: Websters Dictionary (01 Mar 1998) |
| daggle-tail | A slovenly woman; a slattern; a draggle-tail. Source: Websters Dictionary (01 Mar 1998) |
| dog's-tail grass | <botany> A hardy species of British grass (Cynosurus cristatus) which abounds in grass lands, and is well suited for making straw plait. Synonym: goldseed. Source: Websters Dictionary (01 Mar 1998) |
| dragon's tail | See Dragon's blood, Dragon's head, etc, under Dragon. Source: Websters Dictionary (01 Mar 1998) |
| tail | 1. <zoology> The terminal, and usually flexible, posterior appendage of an animal. The tail of mammals and reptiles contains a series of movable vertebrae, and is covered with flesh and hairs or scales like those of other parts of the body. The tail of existing birds consists of several more or less consolidated vertebrae which supports a fanlike group of quills to which the term tail is more particularly applied. The tail of fishes consists of the tapering hind portion of the body ending in a caudal fin. The term tail is sometimes applied to the entire abdomen of a crustacean or insect, and sometimes to the terminal piece or pygidium alone. 2. Any long, flexible terminal appendage; whatever resembles, in shape or position, the tail of an animal, as a catkin. "Doretus writes a great praise of the distilled waters of those tails that hang on willow trees." (Harvey) 3. Hence, the back, last, lower, or inferior part of anything, as opposed to the head, or the superior part. "The Lord will make thee the head, and not the tail." (Deut. Xxviii. 13) 4. A train or company of attendants; a retinue. ""Ah," said he, "if you saw but the chief with his tail on."" (Sir W. Scott) 5. The side of a coin opposite to that which bears the head, effigy, or date; the reverse; rarely used except in the expression "heads or tails," employed when a coin is thrown up for the purpose of deciding some point by its fall. 6. <anatomy> The distal tendon of a muscle. 7. <botany> A downy or feathery appendage to certain achens. It is formed of the permanent elongated style. 8. <surgery> A portion of an incision, at its beginning or end, which does not go through the whole thickness of the skin, and is more painful than a complete incision; called also tailing. One of the strips at the end of a bandage formed by splitting the bandage one or more times. 9. A rope spliced to the strap of a block, by which it may be lashed to anything. 10. The part of a note which runs perpendicularly upward or downward from the head; the stem. 11. Same as Tailing. 12. The bottom or lower portion of a member or part, as a slate or tile. 13. <chemical> See Tailing. Tail beam. Same as Tailpiece. <astronomy> Tail of a comet, the post where the besiegers begin to break ground, and cover themselves from the fire of the place, in advancing the lines of approach. Tail spindle, the spindle of the tailstock of a turning lathe; called also dead spindle. To turn tail, to run away; to flee. "Would she turn tail to the heron, and fly quite out another way; but all was to return in a higher pitch." (Sir P. Sidney) Origin: AS. Taegel, taegl; akin to G. Zagel, Icel. Tagl, Sw. Tagel, Goth. Tagl hair. 59. Source: Websters Dictionary (01 Mar 1998) |
| tail bone | <anatomy> The last bone of the spinal column, sometimes referred to as man's vestigial tail. The last portion of the vertebral column just below the sacrum. (27 Sep 1997) |
| tail bud | The rapidly proliferating mass of cells at the caudal extremity of the embryo; remnant of the primitive node. Synonym: end bud. (05 Mar 2000) |
| tail fold | The ventral folding of the caudal extremity of the embryonic disk. (05 Mar 2000) |
| tail of caudate nucleus | The elongated posterior extension of the caudate nucleus that parallels the body and inferior horn of the lateral ventricle. Synonym: cauda nuclei caudati, cauda striati. (05 Mar 2000) |
| tail of dentate gyrus | A slender whitish band, the attenuated anterior continuation of the dentate gyrus (fascia dentata), crossing transversally the surface of the recurved part of the uncus gyri parahippocampalis. Synonym: band of Giacomini, cauda fasciae dentatae, frenulum of Giacomini, tail of dentate gyrus. (05 Mar 2000) |