Blepharisma
Encyclopedia
Blepharisma is a genus
of heterotrich
family ciliate
s (a type of protist
a) which contains many species. Its members are elongated and roughly egg-shaped, with a contractile vacuole
without collecting channels. Typically, they are pigmented with some shade of red or pink. The anterior pole is bluntly pointed, while the posterior pole is blunted. The body is noncontractile, even within the same culture. They are commonly viewed under microscopes in science classes, as they are generally readily available from scientific supply stores.
, unlike some other ciliates. They exchange nuclear products that results in the reshuffling of hereditary characteristics, as in sexual reproduction
. Conjugation does not always result in immediate increase in numbers, but often it is immediately followed by binary fission.
A pair of ciliates is less agile than the individuals. They still spin, and in general they move together, but at times they appear to conflict or to attempt to pull in different directions. There is a slower rotation with the pair, but they do move up and down in and out of the focus of the microscope. Finding conjugating pairs is more difficult than finding individuals.
. Because of its cilia on all sides, Blepharisma can turn in any direction and often spins around. It spirals as well as spins in a circular motion. It can change direction very easily, which makes it somewhat difficult to keep in view on a microscope. They use their cillia as well as to sweep food into their buccal cavity (mouth).
Blepharisma is particularly notable because of its unusual color. Unlike most protists, they are a faint shade of pink. This is not visible under brightfield illumination.They vary in color, but the colors that are most abundant are yellow, green, and brown. These colors are dull, not bright.
If kept at room temperature Blepharisma moves very quickly, making it difficult to keep it in view by moving the microscope stage. After being placed into a refrigerator for several hours, they slow down notably making them easier to follow. Various substances such as glycerin can be used to suspend or greatly deter motion. However, chilling the specimen is sufficient for viewing their normal movement.
varies from the standard one. In Blepharisma, UAG codes for Glutamine
instead of a stop codon
.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of heterotrich
Heterotrich
The heterotrichs are a class of ciliates. They typically have a prominent adoral zone of membranelles circling the mouth, used in locomotion and feeding, and shorter cilia on the rest of the body. Many species are highly contractile, and are typically compressed or conical in form...
family ciliate
Ciliate
The ciliates are a group of protozoans characterized by the presence of hair-like organelles called cilia, which are identical in structure to flagella but typically shorter and present in much larger numbers with a different undulating pattern than flagella...
s (a type of protist
Protist
Protists are a diverse group of eukaryotic microorganisms. Historically, protists were treated as the kingdom Protista, which includes mostly unicellular organisms that do not fit into the other kingdoms, but this group is contested in modern taxonomy...
a) which contains many species. Its members are elongated and roughly egg-shaped, with a contractile vacuole
Contractile vacuole
A contractile vacuole is a sub-cellular structure involved in osmoregulation. It is found predominantly in protists and in unicellular algae. It was previously known as pulsatile or pulsating vacuole....
without collecting channels. Typically, they are pigmented with some shade of red or pink. The anterior pole is bluntly pointed, while the posterior pole is blunted. The body is noncontractile, even within the same culture. They are commonly viewed under microscopes in science classes, as they are generally readily available from scientific supply stores.
Reproduction
Blepharisma is a poisonous species by going through the four phases of binary fission. They also make use of conjugationBacterial conjugation
Bacterial conjugation is the transfer of genetic material between bacterial cells by direct cell-to-cell contact or by a bridge-like connection between two cells...
, unlike some other ciliates. They exchange nuclear products that results in the reshuffling of hereditary characteristics, as in sexual reproduction
Sexual reproduction
Sexual reproduction is the creation of a new organism by combining the genetic material of two organisms. There are two main processes during sexual reproduction; they are: meiosis, involving the halving of the number of chromosomes; and fertilization, involving the fusion of two gametes and the...
. Conjugation does not always result in immediate increase in numbers, but often it is immediately followed by binary fission.
A pair of ciliates is less agile than the individuals. They still spin, and in general they move together, but at times they appear to conflict or to attempt to pull in different directions. There is a slower rotation with the pair, but they do move up and down in and out of the focus of the microscope. Finding conjugating pairs is more difficult than finding individuals.
Cilia and Movement
Blepharisma is covered in tiny hairlike parts called cilia, which allows it to move through water - more slowly than vinegar eels, but faster than VolvoxVolvox
Volvox is a genus of chlorophytes, a type of green algae. It forms spherical colonies of up to 50,000 cells. They live in a variety of freshwater habitats, and were first reported by Antonie van Leeuwenhoek in 1700. Volvox developed its colonial lifestyle .-Description:Volvox is the most developed...
. Because of its cilia on all sides, Blepharisma can turn in any direction and often spins around. It spirals as well as spins in a circular motion. It can change direction very easily, which makes it somewhat difficult to keep in view on a microscope. They use their cillia as well as to sweep food into their buccal cavity (mouth).
Feeding
As Blepharisma is a microphagus filter feeder and a ciliate, it is classified in the phylum Ciliophora. It generally eats bacteria from decomposing vegetation, which is drawn into the buccal cavity and then passes to the food vacuoles at the posterior end of the cell.Appearance
Blepharisma ranges in size from approximately 150 to 300 micrometers.Blepharisma is particularly notable because of its unusual color. Unlike most protists, they are a faint shade of pink. This is not visible under brightfield illumination.They vary in color, but the colors that are most abundant are yellow, green, and brown. These colors are dull, not bright.
Behavior
Despite the availability of many still images displaying their structure, there is still little information regarding the behavior and movement of Blepharisma. Still images can provide excellent views of their internal organelles, but video footage is necessary to view their movement. However, as with any small, transparent moving organism there are challenges involved in video recording which have yet to be overcome.If kept at room temperature Blepharisma moves very quickly, making it difficult to keep it in view by moving the microscope stage. After being placed into a refrigerator for several hours, they slow down notably making them easier to follow. Various substances such as glycerin can be used to suspend or greatly deter motion. However, chilling the specimen is sufficient for viewing their normal movement.
Genetic Code
Blepharisma's genetic codeGenetic code
The genetic code is the set of rules by which information encoded in genetic material is translated into proteins by living cells....
varies from the standard one. In Blepharisma, UAG codes for Glutamine
Glutamine
Glutamine is one of the 20 amino acids encoded by the standard genetic code. It is not recognized as an essential amino acid but may become conditionally essential in certain situations, including intensive athletic training or certain gastrointestinal disorders...
instead of a stop codon
Stop codon
In the genetic code, a stop codon is a nucleotide triplet within messenger RNA that signals a termination of translation. Proteins are based on polypeptides, which are unique sequences of amino acids. Most codons in messenger RNA correspond to the addition of an amino acid to a growing polypeptide...
.