Gulshan Sapra - Academia.edu (original) (raw)

Papers by Gulshan Sapra

Research paper thumbnail of Ciliates of the Silent Valley National Park, India: Urostyloid Hypotrichs of the Region with a Note on the Habitat

Acta Protozoologica, 2010

... Address for correspondence: Dr. Komal Kamra, Associate Profes-sor of Zoology, Sri Guru Tegh B... more ... Address for correspondence: Dr. Komal Kamra, Associate Profes-sor of Zoology, Sri Guru Tegh Bahadur Khalsa College, University of Delhi, Delhi-110007 ... Type locality: Light brown soil from the tropical rain forest close to the entry point (Sairandri) of the Si-lent Valley National ...

Research paper thumbnail of Coniculostomum bimarginata n. sp., a new hypotrich ciliate: Description and systematic relationships

The hypotrich ciliate Coniculostomum bimarginata n. sp. is characterized by an average size of 16... more The hypotrich ciliate Coniculostomum bimarginata n. sp. is characterized by an average size of 167.3 [lm X 84.1 urn, 18 cirri in the frontal ciliature, 2 rows of right marginal cirri (RMC), a single row of left marginal cirri, 4 dorsal kineties, and 3-4 dorsomarginal rows (DMs). During division only one RMC row and two DM rows are produced; additional RMC and DM rows are the persistent parental ciliature that is distributed to the two daughter cells.

Research paper thumbnail of Morphology, Morphogenesis, and Molecular Phylogeny of Anteholosticha multicirrata n. sp. (Ciliophora, Spirotrichea) with a Note on Morphogenesis of A. pulchra (Kahl, 1932) Berger, 2003

Journal of Eukaryotic Microbiology, 2013

Research paper thumbnail of Persistent hyperthermia induces adaptive modulations in the cytology of ciliates Stylonychia mytilus and Euplotes aediculatus

Journal of Thermal Biology, 1989

Al~tract--l. Laboratory cultures of S. mytilus and E. aediculatus adapt maximally upto 30°C. Cell... more Al~tract--l. Laboratory cultures of S. mytilus and E. aediculatus adapt maximally upto 30°C. Cells adapted at this limit appear normal in their growth characteristics and morphology. However, hyperthermic growth induces marked changes in the macronuclear cytomorphology and significant increase in macronuclear size. Besides, nearly all cells exhibit a variety of anomalies in the DNA synthesis pattern.

Research paper thumbnail of Variation in Sensitivity to Heat Shock during the Cell-cycle of Chinese Hamster Cells in Vitro

International Journal of Radiation Biology, 1971

When asynchronous cells were exposed for 4-100 rain to heat shocks of 43"5- 46"5°c, a s... more When asynchronous cells were exposed for 4-100 rain to heat shocks of 43"5- 46"5°c, a sigrnoidal relationship between survival and duration of heat treatment was observed. From an Arrhenius plot, an activation energy of 140 800 cal/mole was calculated, which is similar to that ...

Research paper thumbnail of Morphology, ontogenesis, and molecular phylogeny of an Indian population of Cyrtohymena (Cyrtohymenides) shii, including remarks on the subgenus

European Journal of Protistology, 2013

Research paper thumbnail of Formation of a transient corticotype during excystment in Coniculostomum monilata (oxytrichidae, hypotrichida) and its modification by reorganizations

European Journal of Protistology, 1991

Protargol impregnation revealed that Coniculostomum monilata, an advanced oxytrichid ciliate with... more Protargol impregnation revealed that Coniculostomum monilata, an advanced oxytrichid ciliate with the typical 18 Frontal-Ventral-Transverse (FVT) cirri but with multiple rows of right marginal cirri (RMC) and dorso-marginal cilia (DM), requires at least 3 morphogenetic cycles to acquire the normal vegetative ciliature during excystment. In the first cycle, the FVT cirral pattern is entirely different from that formed during division. The 'first ciliature' comprises 21-32 FVT cirri formed from 5 FVT primordia; these are substituted by 18 FVT cirri developed from 6 FVT primordia in the subsequent reorganization cycle. Furthermore, each successive cycle adds one RMC row and 2 DM rows while previous rows are not resorbed, unlike the FVT cirri and the left marginal cirri. Consequently, multiple RMC and DM rows develop to form a typical vegetative corticotype. Dual information for frontal ciliature appears to be a unique feature of C. monilata as a similar situation has not been observed in the other evolved oxytrichids. Presence of an alternate corticotype information (> 18 FVT cirri) possibly signifies phylogenetic relationship of C. monilata with the lower oxytrichids. Excystment morphogenesis data reaffirms the conclusion from previous investigations that C. monilata has inherited information for only 1 RMC row and 2 DM rows; multiple rows are attained through a characteristic retention of pre-existing/parental rows.

Research paper thumbnail of Coniculostomum bimarginata n. sp., a new hypotrich ciliate: Description and systematic relationships

European Journal of Protistology, 1994

The hypotrich ciliate Coniculostomum bimarginata n. sp. is characterized by an average size of 16... more The hypotrich ciliate Coniculostomum bimarginata n. sp. is characterized by an average size of 167.3 [lm X 84.1 urn, 18 cirri in the frontal ciliature, 2 rows of right marginal cirri (RMC), a single row of left marginal cirri, 4 dorsal kineties, and 3-4 dorsomarginal rows (DMs). During division only one RMC row and two DM rows are produced; additional RMC and DM rows are the persistent parental ciliature that is distributed to the two daughter cells.

Research paper thumbnail of Partial retention of parental ciliature during morphogenesis of the ciliate Coniculostomum monilata (Dragesco & Njiné, 1971) Njiné, 1978 (Oxytrichidae, Hypotrichida)

European Journal of Protistology, 1990

Morphogenesis of Coniculostomum monilata as revealed by protargol staining shows formation of 18 ... more Morphogenesis of Coniculostomum monilata as revealed by protargol staining shows formation of 18 Frontal-Ventral-Transverse (FVT) cirri from 6 cirral streaks. Only 3 parental FVT cirri participate in the formation of cirral streaks. While only one row of right marginal cirri (RMC) is formed during division, the non-dividing cell possesses 3-5 RMC rows. This corticotype is explained by the fact that during division parental RMC rows are retained and inwardly displaced, the innermost row being resorbed. As the cell elongates, cirri in the retained rows space out; each row is equatorially cleaved during cytokinesis. A similar retention of dorsomarginal rows occurs on the dorsal surface. Based on synapomorphies shared by C. monilata and Stylonychia mytilus, we propose that C. monilata is an evolved oxytrichid. The regular retention of ciliary structures through several generations is, however, a unique character amongst the evolved oxytrichids and may be considered as an autapomorphy to describe C. monilata. Another such feature of C. monilata is the moniliform macronucleus, unique among the advanced oxytrichids. The present study reaffirms the importance of morphogenetic criteria in ciliate systematics. The original description of C. monilata Njiné, 1978 has been rectified with respect to the nomenclature of cirri and phylogenetic status of the species.

Research paper thumbnail of Quantitative regulation of ciliary structures in polymorphic states of the hypotrichous ciliate Onychodromus indica, Kamra and Sapra 1993

European Journal of Protistology, 1994

Research paper thumbnail of Influence of cadmium on development of surface ciliary structures in the ciliate Stylonychia mytilus (Ciliophora, Oxytrichidae)

European Journal of Protistology, 1999

The effect of cadmium on the morphogenesis and patterning of surface ciliary structures has been ... more The effect of cadmium on the morphogenesis and patterning of surface ciliary structures has been analyzed in the ciliate protozoan Stylonychia mytilus. During division and cortical reorganization, Stylonychia cells exhibit development of ciliary structures, consisting of an adoral zone of membranelles (AZM), two undulating membranes, Irontoventral-transverse (FVf) cirri, a row each of right and left marginal cirri, dorsal kineties and caudal cirri which differentiate from their respective ciliary primordia. Subsequent patterning results in a species specific spatial arrangement of ciliary structures. The presence of cadmium in the culture medium disturbs the development process in that the cells develop supernumerary ciliary primordia which differentiate to form 3-7 extra FVT cirri, one or more additional dorsal kineties, and caudal cirri. The additional cirri exhibit quantitative features which are characteristic of their spatial position on the cell surface. The anomalous ciliary patterns are transitory and are reversed when cells divide or reorganize in the cadmium free medium. In the presence of cadmium, configuration of the new AZM becomes distorted as the newly differentiated membranelles near the cytostome fail to align correctly due to their torsional displacement. Development of additional ciliary structures is not accompanied by significant morphometric changes in the cells.

Research paper thumbnail of Ciliates of the Silent Valley National Park, India: Urostyloid Hypotrichs of the Region with a Note on the Habitat

Acta Protozoologica, 2010

... Address for correspondence: Dr. Komal Kamra, Associate Profes-sor of Zoology, Sri Guru Tegh B... more ... Address for correspondence: Dr. Komal Kamra, Associate Profes-sor of Zoology, Sri Guru Tegh Bahadur Khalsa College, University of Delhi, Delhi-110007 ... Type locality: Light brown soil from the tropical rain forest close to the entry point (Sairandri) of the Si-lent Valley National ...

Research paper thumbnail of Pleurotricha indica n. sp., a New Hypotrich Ciliate from the Indian Subcontinent1

The Journal of Protozoology, 1987

ABSTRACT

Research paper thumbnail of Ciliates of the Silent Valley National Park, India: Urostyloid Hypotrichs of the Region with a Note on the Habitat

Acta Protozoologica, 2010

... Address for correspondence: Dr. Komal Kamra, Associate Profes-sor of Zoology, Sri Guru Tegh B... more ... Address for correspondence: Dr. Komal Kamra, Associate Profes-sor of Zoology, Sri Guru Tegh Bahadur Khalsa College, University of Delhi, Delhi-110007 ... Type locality: Light brown soil from the tropical rain forest close to the entry point (Sairandri) of the Si-lent Valley National ...

Research paper thumbnail of Coniculostomum bimarginata n. sp., a new hypotrich ciliate: Description and systematic relationships

The hypotrich ciliate Coniculostomum bimarginata n. sp. is characterized by an average size of 16... more The hypotrich ciliate Coniculostomum bimarginata n. sp. is characterized by an average size of 167.3 [lm X 84.1 urn, 18 cirri in the frontal ciliature, 2 rows of right marginal cirri (RMC), a single row of left marginal cirri, 4 dorsal kineties, and 3-4 dorsomarginal rows (DMs). During division only one RMC row and two DM rows are produced; additional RMC and DM rows are the persistent parental ciliature that is distributed to the two daughter cells.

Research paper thumbnail of Morphology, Morphogenesis, and Molecular Phylogeny of Anteholosticha multicirrata n. sp. (Ciliophora, Spirotrichea) with a Note on Morphogenesis of A. pulchra (Kahl, 1932) Berger, 2003

Journal of Eukaryotic Microbiology, 2013

Research paper thumbnail of Persistent hyperthermia induces adaptive modulations in the cytology of ciliates Stylonychia mytilus and Euplotes aediculatus

Journal of Thermal Biology, 1989

Al~tract--l. Laboratory cultures of S. mytilus and E. aediculatus adapt maximally upto 30°C. Cell... more Al~tract--l. Laboratory cultures of S. mytilus and E. aediculatus adapt maximally upto 30°C. Cells adapted at this limit appear normal in their growth characteristics and morphology. However, hyperthermic growth induces marked changes in the macronuclear cytomorphology and significant increase in macronuclear size. Besides, nearly all cells exhibit a variety of anomalies in the DNA synthesis pattern.

Research paper thumbnail of Variation in Sensitivity to Heat Shock during the Cell-cycle of Chinese Hamster Cells in Vitro

International Journal of Radiation Biology, 1971

When asynchronous cells were exposed for 4-100 rain to heat shocks of 43"5- 46"5°c, a s... more When asynchronous cells were exposed for 4-100 rain to heat shocks of 43"5- 46"5°c, a sigrnoidal relationship between survival and duration of heat treatment was observed. From an Arrhenius plot, an activation energy of 140 800 cal/mole was calculated, which is similar to that ...

Research paper thumbnail of Morphology, ontogenesis, and molecular phylogeny of an Indian population of Cyrtohymena (Cyrtohymenides) shii, including remarks on the subgenus

European Journal of Protistology, 2013

Research paper thumbnail of Formation of a transient corticotype during excystment in Coniculostomum monilata (oxytrichidae, hypotrichida) and its modification by reorganizations

European Journal of Protistology, 1991

Protargol impregnation revealed that Coniculostomum monilata, an advanced oxytrichid ciliate with... more Protargol impregnation revealed that Coniculostomum monilata, an advanced oxytrichid ciliate with the typical 18 Frontal-Ventral-Transverse (FVT) cirri but with multiple rows of right marginal cirri (RMC) and dorso-marginal cilia (DM), requires at least 3 morphogenetic cycles to acquire the normal vegetative ciliature during excystment. In the first cycle, the FVT cirral pattern is entirely different from that formed during division. The 'first ciliature' comprises 21-32 FVT cirri formed from 5 FVT primordia; these are substituted by 18 FVT cirri developed from 6 FVT primordia in the subsequent reorganization cycle. Furthermore, each successive cycle adds one RMC row and 2 DM rows while previous rows are not resorbed, unlike the FVT cirri and the left marginal cirri. Consequently, multiple RMC and DM rows develop to form a typical vegetative corticotype. Dual information for frontal ciliature appears to be a unique feature of C. monilata as a similar situation has not been observed in the other evolved oxytrichids. Presence of an alternate corticotype information (> 18 FVT cirri) possibly signifies phylogenetic relationship of C. monilata with the lower oxytrichids. Excystment morphogenesis data reaffirms the conclusion from previous investigations that C. monilata has inherited information for only 1 RMC row and 2 DM rows; multiple rows are attained through a characteristic retention of pre-existing/parental rows.

Research paper thumbnail of Coniculostomum bimarginata n. sp., a new hypotrich ciliate: Description and systematic relationships

European Journal of Protistology, 1994

The hypotrich ciliate Coniculostomum bimarginata n. sp. is characterized by an average size of 16... more The hypotrich ciliate Coniculostomum bimarginata n. sp. is characterized by an average size of 167.3 [lm X 84.1 urn, 18 cirri in the frontal ciliature, 2 rows of right marginal cirri (RMC), a single row of left marginal cirri, 4 dorsal kineties, and 3-4 dorsomarginal rows (DMs). During division only one RMC row and two DM rows are produced; additional RMC and DM rows are the persistent parental ciliature that is distributed to the two daughter cells.

Research paper thumbnail of Partial retention of parental ciliature during morphogenesis of the ciliate Coniculostomum monilata (Dragesco & Njiné, 1971) Njiné, 1978 (Oxytrichidae, Hypotrichida)

European Journal of Protistology, 1990

Morphogenesis of Coniculostomum monilata as revealed by protargol staining shows formation of 18 ... more Morphogenesis of Coniculostomum monilata as revealed by protargol staining shows formation of 18 Frontal-Ventral-Transverse (FVT) cirri from 6 cirral streaks. Only 3 parental FVT cirri participate in the formation of cirral streaks. While only one row of right marginal cirri (RMC) is formed during division, the non-dividing cell possesses 3-5 RMC rows. This corticotype is explained by the fact that during division parental RMC rows are retained and inwardly displaced, the innermost row being resorbed. As the cell elongates, cirri in the retained rows space out; each row is equatorially cleaved during cytokinesis. A similar retention of dorsomarginal rows occurs on the dorsal surface. Based on synapomorphies shared by C. monilata and Stylonychia mytilus, we propose that C. monilata is an evolved oxytrichid. The regular retention of ciliary structures through several generations is, however, a unique character amongst the evolved oxytrichids and may be considered as an autapomorphy to describe C. monilata. Another such feature of C. monilata is the moniliform macronucleus, unique among the advanced oxytrichids. The present study reaffirms the importance of morphogenetic criteria in ciliate systematics. The original description of C. monilata Njiné, 1978 has been rectified with respect to the nomenclature of cirri and phylogenetic status of the species.

Research paper thumbnail of Quantitative regulation of ciliary structures in polymorphic states of the hypotrichous ciliate Onychodromus indica, Kamra and Sapra 1993

European Journal of Protistology, 1994

Research paper thumbnail of Influence of cadmium on development of surface ciliary structures in the ciliate Stylonychia mytilus (Ciliophora, Oxytrichidae)

European Journal of Protistology, 1999

The effect of cadmium on the morphogenesis and patterning of surface ciliary structures has been ... more The effect of cadmium on the morphogenesis and patterning of surface ciliary structures has been analyzed in the ciliate protozoan Stylonychia mytilus. During division and cortical reorganization, Stylonychia cells exhibit development of ciliary structures, consisting of an adoral zone of membranelles (AZM), two undulating membranes, Irontoventral-transverse (FVf) cirri, a row each of right and left marginal cirri, dorsal kineties and caudal cirri which differentiate from their respective ciliary primordia. Subsequent patterning results in a species specific spatial arrangement of ciliary structures. The presence of cadmium in the culture medium disturbs the development process in that the cells develop supernumerary ciliary primordia which differentiate to form 3-7 extra FVT cirri, one or more additional dorsal kineties, and caudal cirri. The additional cirri exhibit quantitative features which are characteristic of their spatial position on the cell surface. The anomalous ciliary patterns are transitory and are reversed when cells divide or reorganize in the cadmium free medium. In the presence of cadmium, configuration of the new AZM becomes distorted as the newly differentiated membranelles near the cytostome fail to align correctly due to their torsional displacement. Development of additional ciliary structures is not accompanied by significant morphometric changes in the cells.

Research paper thumbnail of Ciliates of the Silent Valley National Park, India: Urostyloid Hypotrichs of the Region with a Note on the Habitat

Acta Protozoologica, 2010

... Address for correspondence: Dr. Komal Kamra, Associate Profes-sor of Zoology, Sri Guru Tegh B... more ... Address for correspondence: Dr. Komal Kamra, Associate Profes-sor of Zoology, Sri Guru Tegh Bahadur Khalsa College, University of Delhi, Delhi-110007 ... Type locality: Light brown soil from the tropical rain forest close to the entry point (Sairandri) of the Si-lent Valley National ...

Research paper thumbnail of Pleurotricha indica n. sp., a New Hypotrich Ciliate from the Indian Subcontinent1

The Journal of Protozoology, 1987

ABSTRACT