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Hilary A. Mcmanus - One of the best experts on this subject based on the ideXlab platform.

  • Plastomes of the green algae Hydrodictyon reticulatum and Pediastrum duplex (Sphaeropleales, Chlorophyceae)
    PeerJ, 2017
    Co-Authors: Hilary A. Mcmanus, Daniel J. Sanchez, Kenneth G. Karol
    Abstract:

    Background Comparative studies of chloroplast genomes (plastomes) across the Chlorophyceae are revealing dynamic patterns of size variation, gene content, and genome rearrangements. Phylogenomic analyses are improving resolution of relationships, and uncovering novel lineages as new plastomes continue to be characterized. To gain further insight into the evolution of the chlorophyte plastome and increase the number of representative plastomes for the Sphaeropleales, this study presents two fully sequenced plastomes from the green algal family Hydrodictyaceae (Sphaeropleales, Chlorophyceae), one from Hydrodictyon reticulatum and the other from Pediastrum duplex. Methods Genomic DNA from Hydrodictyon reticulatum and Pediastrum duplex was subjected to Illumina paired-end sequencing and the complete plastomes were assembled for each. Plastome size and gene content were characterized and compared with other plastomes from the Sphaeropleales. Homology searches using BLASTX were used to characterize introns and open reading frames (orfs) ≥ 300 bp. A phylogenetic analysis of gene order across the Sphaeropleales was performed. Results The plastome of Hydrodictyon reticulatum is 225,641 bp and Pediastrum duplex is 232,554 bp. The plastome structure and gene order of H. reticulatum and P. duplex are more similar to each other than to other members of the Sphaeropleales. Numerous unique open reading frames are found in both plastomes and the plastome of P. duplex contains putative viral protein genes, not found in other Sphaeropleales plastomes. Gene order analyses support the monophyly of the Hydrodictyaceae and their sister relationship to the Neochloridaceae. Discussion The complete plastomes of Hydrodictyon reticulatum and Pediastrum duplex, representing the largest of the Sphaeropleales sequenced thus far, once again highlight the variability in size, architecture, gene order and content across the Chlorophyceae. Novel intron insertion sites and unique orfs indicate recent, independent invasions into each plastome, a hypothesis testable with an expanded plastome investigation within the Hydrodictyaceae.

  • Molecular phylogenetics, morphological variation and colony-form evolution in the family Hydrodictyaceae (Sphaeropleales, Chlorophyta)
    Phycologia, 2005
    Co-Authors: Hilary A. Mcmanus, Louise A. Lewis
    Abstract:

    Abstract A phylogenetic analysis of 26S and internal transcribed spacer–2 ribosomal DNA (rDNA) data from members of the freshwater green algal family Hydrodictyaceae, including multiple taxa from both culture collections and new isolates, sets the stage to explore morphological variation and patterns of colony-form evolution within the family. These analyses particularly focus on Pediastrum boryanum, P. tetras, P. duplex, Hydrodictyon and Sorastrum. The genera Hydrodictyon and Sorastrum are derived from within Pediastrum in the individual and combined analyses, indicating a pattern of colony-form evolution within the family from two-dimensionality to three-dimensionality. In some cases the gene topologies reveal discrepancies in the morphological characters used to delimit species, varieties and forms within Pediastrum. Some isolates, such as those of H. reticulatum, exhibited little or no genetic variation between different geographic localities. Additional data and taxa are needed to better resolve and ...

  • Phylogenetic Relationships Among Pediastrum sPP. and Hydrodictyon sPP.
    Journal of Phycology, 2002
    Co-Authors: Hilary A. Mcmanus, Louise A. Lewis
    Abstract:

    Within the class Chlorophyceae, the family Hydrodictyaceae (order Sphaeropleales) consists of taxa that form flat or net-like coenobia and reproduce asexually by way of biflagellated zoospores. Two taxa within this family, Pediastrum and Hydrodictyon, share many features during development, especially the manner of daughter colony formation. The colonies of Pediastrum differ from Hydrodictyon in that growth is planar resulting in two-dimensional colonies, while three-dimensional nets are formed in Hydrodictyon. Studies of the Chlorophyceae using morphological and ultrastructural data, as well as molecular sequence data, have supported the close relationship of Pediastrum and Hydrodictyon and they have remained in the family Hydrodictyaceae throughout major classification revisions. However, in these studies only single species of Pediastrum (P. duplex) and Hydrodictyon (H. reticulatum) were included, therefore the exact relationship of these two taxa could not be explored. Preliminary molecular data from a second species of Pediastrum, P. boryanum, indicate that Hydrodictyon may be derived from Pediastrum. In this analysis, H. reticulatum resolves as sister taxon to P. duplex with P. boryanum the ancestral taxon. Further molecular studies of the family Hydrodictyaceae allow exploration of the relationships between Pediastrum spp. and Hydrodictyon spp., and assist in determining whether they are monophyletic. Preliminary analyses include H. reticulatum and H. africanum and several species of Pediastrum, P. duplex, P. boryanum, P. tetras, P. biradiatum and P. simplex. An understanding of the phylogenetic relationships among the species of Pediastrum and Hydrodictyon will allow a more complete comparison of colony formation.

Louise A. Lewis - One of the best experts on this subject based on the ideXlab platform.

  • Molecular phylogenetics, morphological variation and colony-form evolution in the family Hydrodictyaceae (Sphaeropleales, Chlorophyta)
    Phycologia, 2005
    Co-Authors: Hilary A. Mcmanus, Louise A. Lewis
    Abstract:

    Abstract A phylogenetic analysis of 26S and internal transcribed spacer–2 ribosomal DNA (rDNA) data from members of the freshwater green algal family Hydrodictyaceae, including multiple taxa from both culture collections and new isolates, sets the stage to explore morphological variation and patterns of colony-form evolution within the family. These analyses particularly focus on Pediastrum boryanum, P. tetras, P. duplex, Hydrodictyon and Sorastrum. The genera Hydrodictyon and Sorastrum are derived from within Pediastrum in the individual and combined analyses, indicating a pattern of colony-form evolution within the family from two-dimensionality to three-dimensionality. In some cases the gene topologies reveal discrepancies in the morphological characters used to delimit species, varieties and forms within Pediastrum. Some isolates, such as those of H. reticulatum, exhibited little or no genetic variation between different geographic localities. Additional data and taxa are needed to better resolve and ...

  • Phylogenetic Relationships Among Pediastrum sPP. and Hydrodictyon sPP.
    Journal of Phycology, 2002
    Co-Authors: Hilary A. Mcmanus, Louise A. Lewis
    Abstract:

    Within the class Chlorophyceae, the family Hydrodictyaceae (order Sphaeropleales) consists of taxa that form flat or net-like coenobia and reproduce asexually by way of biflagellated zoospores. Two taxa within this family, Pediastrum and Hydrodictyon, share many features during development, especially the manner of daughter colony formation. The colonies of Pediastrum differ from Hydrodictyon in that growth is planar resulting in two-dimensional colonies, while three-dimensional nets are formed in Hydrodictyon. Studies of the Chlorophyceae using morphological and ultrastructural data, as well as molecular sequence data, have supported the close relationship of Pediastrum and Hydrodictyon and they have remained in the family Hydrodictyaceae throughout major classification revisions. However, in these studies only single species of Pediastrum (P. duplex) and Hydrodictyon (H. reticulatum) were included, therefore the exact relationship of these two taxa could not be explored. Preliminary molecular data from a second species of Pediastrum, P. boryanum, indicate that Hydrodictyon may be derived from Pediastrum. In this analysis, H. reticulatum resolves as sister taxon to P. duplex with P. boryanum the ancestral taxon. Further molecular studies of the family Hydrodictyaceae allow exploration of the relationships between Pediastrum spp. and Hydrodictyon spp., and assist in determining whether they are monophyletic. Preliminary analyses include H. reticulatum and H. africanum and several species of Pediastrum, P. duplex, P. boryanum, P. tetras, P. biradiatum and P. simplex. An understanding of the phylogenetic relationships among the species of Pediastrum and Hydrodictyon will allow a more complete comparison of colony formation.

Aloisie Poulíčková - One of the best experts on this subject based on the ideXlab platform.

John S. Clayton - One of the best experts on this subject based on the ideXlab platform.

  • Ecological impacts of water net (Hydrodictyon reticulatum) in Lake Aniwhenua, New Zealand.
    New Zealand Journal of Ecology, 2001
    Co-Authors: Rohan D. S. Wells, John S. Clayton
    Abstract:

    The ecological impacts of Hydrodictyon reticulatum blooms (1989-94) were studied at Lake Aniwhenua (a constructed lake) in North Island, New Zealand by collating fish, invertebrate and macrophyte data collected towards the end of a four year bloom period and following its decline. Hydrodictyon reticulatum had some localised impacts on the biota of the lake. Some macrophyte beds were smothered to the extent that they collapsed and disappeared, and dense compacted accumulations of H. reticulatum caused localised anoxic conditions while it decayed. However, fish and some invertebrates in the lake benefited from the H. reticulatum blooms. High numbers of Ceriodaphnia sp. (maximum, 5.5 x 104 m -2 ) were recorded amongst H. reticulatum, and gastropods were exceptionally abundant, the most common being Potamopyrgus antipodarum (maximum, 1.8 x IOS m -2 ). Hydrodictyon reticulatum was consumed by three species of common gastropods in experimental trials, with Austropeplea tomentosa consuming up to 1.3 g dry weight H. reticulatum g -1 ,live weight of snail day -1 . Gastropods comprised the major portion of the diet of Oncorhynchus mykiss in Lake Aniwhenua during and after the H. reticulatum bloom. A marked peak in sports fishing (with exceptional sizes and numbers of fish caught) coincided with the period of H. reticulatum blooms and the abundant invertebrate food source associated with the blooms.

  • The Rise and Fall of Water Net (Hydrodictyon reticulatum) in New Zealand
    1999
    Co-Authors: Rohan D. S. Wells, John S. Clayton, J.a. Hall, Paul D. Champion, G.w. Payne, Deborah Hofstra
    Abstract:

    During the late 1980s to early 1990s a range of aquatic habitats in the central North Island of New Zealand were invaded by the filamentous green alga, water net Hydrodictyon reticulatum (Linn. Lagerheim). The alga caused significant economic and recreational impacts at major sites of infestation, but it was also associated with enhanced invertebrate numbers and was the likely cause of an improvement in the trout fishery. The causes of prolific growth of water net and the range of control options pursued are reviewed. The possible causes of its sudden decline in 1995 are considered, including physical factors, increase in grazer pressure, disease, and loss of genetic vigour.

  • Invasion of water net, Hydrodictyon reticulatum: The surprising success of an aquatic plant new to our flora
    New Zealand Journal of Marine and Freshwater Research, 1991
    Co-Authors: Ian Hawes, Rohan D. S. Wells, Clive Howard-williams, John S. Clayton
    Abstract:

    Invasion of water net, Hydrodictyon reticulatum: The surprising success of an aquatic plant new to our flora Ian Hawes a , Clive Howard‐Williams a , Rohan Wells b & John Clayton b a Taupo Research Laboratory, DSIR Marine & Freshwater , P.O. Box 415, Taupo b Aquatic Plant Section, Ruakura Agricultural Research Centre , Ministry of Agriculture & Fisheries , Private Bag, Hamilton Published online: 30 Mar 2010.

Rohan D. S. Wells - One of the best experts on this subject based on the ideXlab platform.

  • Ecological impacts of water net (Hydrodictyon reticulatum) in Lake Aniwhenua, New Zealand.
    New Zealand Journal of Ecology, 2001
    Co-Authors: Rohan D. S. Wells, John S. Clayton
    Abstract:

    The ecological impacts of Hydrodictyon reticulatum blooms (1989-94) were studied at Lake Aniwhenua (a constructed lake) in North Island, New Zealand by collating fish, invertebrate and macrophyte data collected towards the end of a four year bloom period and following its decline. Hydrodictyon reticulatum had some localised impacts on the biota of the lake. Some macrophyte beds were smothered to the extent that they collapsed and disappeared, and dense compacted accumulations of H. reticulatum caused localised anoxic conditions while it decayed. However, fish and some invertebrates in the lake benefited from the H. reticulatum blooms. High numbers of Ceriodaphnia sp. (maximum, 5.5 x 104 m -2 ) were recorded amongst H. reticulatum, and gastropods were exceptionally abundant, the most common being Potamopyrgus antipodarum (maximum, 1.8 x IOS m -2 ). Hydrodictyon reticulatum was consumed by three species of common gastropods in experimental trials, with Austropeplea tomentosa consuming up to 1.3 g dry weight H. reticulatum g -1 ,live weight of snail day -1 . Gastropods comprised the major portion of the diet of Oncorhynchus mykiss in Lake Aniwhenua during and after the H. reticulatum bloom. A marked peak in sports fishing (with exceptional sizes and numbers of fish caught) coincided with the period of H. reticulatum blooms and the abundant invertebrate food source associated with the blooms.

  • The Rise and Fall of Water Net (Hydrodictyon reticulatum) in New Zealand
    1999
    Co-Authors: Rohan D. S. Wells, John S. Clayton, J.a. Hall, Paul D. Champion, G.w. Payne, Deborah Hofstra
    Abstract:

    During the late 1980s to early 1990s a range of aquatic habitats in the central North Island of New Zealand were invaded by the filamentous green alga, water net Hydrodictyon reticulatum (Linn. Lagerheim). The alga caused significant economic and recreational impacts at major sites of infestation, but it was also associated with enhanced invertebrate numbers and was the likely cause of an improvement in the trout fishery. The causes of prolific growth of water net and the range of control options pursued are reviewed. The possible causes of its sudden decline in 1995 are considered, including physical factors, increase in grazer pressure, disease, and loss of genetic vigour.

  • Invasion of water net, Hydrodictyon reticulatum: The surprising success of an aquatic plant new to our flora
    New Zealand Journal of Marine and Freshwater Research, 1991
    Co-Authors: Ian Hawes, Rohan D. S. Wells, Clive Howard-williams, John S. Clayton
    Abstract:

    Invasion of water net, Hydrodictyon reticulatum: The surprising success of an aquatic plant new to our flora Ian Hawes a , Clive Howard‐Williams a , Rohan Wells b & John Clayton b a Taupo Research Laboratory, DSIR Marine & Freshwater , P.O. Box 415, Taupo b Aquatic Plant Section, Ruakura Agricultural Research Centre , Ministry of Agriculture & Fisheries , Private Bag, Hamilton Published online: 30 Mar 2010.